diff --git a/backend/core/migrations/0045_riskassessment_ebios_rm_study.py b/backend/core/migrations/0045_riskassessment_ebios_rm_study.py
new file mode 100644
index 0000000000..e47dd700e3
--- /dev/null
+++ b/backend/core/migrations/0045_riskassessment_ebios_rm_study.py
@@ -0,0 +1,20 @@
+# Generated by Django 5.1.1 on 2024-12-09 15:43
+
+import django.db.models.deletion
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('core', '0044_qualification'),
+        ('ebios_rm', '0002_remove_ebiosrmstudy_risk_assessments'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='riskassessment',
+            name='ebios_rm_study',
+            field=models.ForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.CASCADE, related_name='risk_assessments', to='ebios_rm.ebiosrmstudy', verbose_name='EBIOS RM study'),
+        ),
+    ]
diff --git a/backend/core/models.py b/backend/core/models.py
index 5ab669cfd1..dcd25b8be1 100644
--- a/backend/core/models.py
+++ b/backend/core/models.py
@@ -1980,6 +1980,14 @@ class RiskAssessment(Assessment):
     ref_id = models.CharField(
         max_length=100, null=True, blank=True, verbose_name=_("reference id")
     )
+    ebios_rm_study = models.ForeignKey(
+        "ebios_rm.EbiosRMStudy",
+        verbose_name=_("EBIOS RM study"),
+        on_delete=models.CASCADE,
+        null=True,
+        blank=True,
+        related_name="risk_assessments",
+    )
 
     class Meta:
         verbose_name = _("Risk assessment")
diff --git a/backend/core/serializers.py b/backend/core/serializers.py
index 7ad0ee414e..701b00320b 100644
--- a/backend/core/serializers.py
+++ b/backend/core/serializers.py
@@ -191,13 +191,6 @@ class Meta:
 
 
 class RiskAssessmentWriteSerializer(BaseModelSerializer):
-    ebios_rm_studies = serializers.PrimaryKeyRelatedField(
-        many=True,
-        queryset=EbiosRMStudy.objects.all(),
-        required=False,
-        allow_null=True,
-        write_only=True,
-    )
     
     class Meta:
         model = RiskAssessment
@@ -220,7 +213,7 @@ class RiskAssessmentReadSerializer(AssessmentReadSerializer):
 
     class Meta:
         model = RiskAssessment
-        fields = "__all__"
+        exclude = ["ebios_rm_study"]
 
 
 class AssetWriteSerializer(BaseModelSerializer):
diff --git a/backend/core/views.py b/backend/core/views.py
index a1b14eb5e6..cabe0ceb5d 100644
--- a/backend/core/views.py
+++ b/backend/core/views.py
@@ -568,7 +568,7 @@ class RiskAssessmentViewSet(BaseModelViewSet):
         "authors",
         "risk_matrix",
         "status",
-        "ebios_rm_studies"
+        "ebios_rm_study"
     ]
 
     @action(detail=False, name="Risk assessments per status")
diff --git a/backend/ebios_rm/migrations/0002_remove_ebiosrmstudy_risk_assessments.py b/backend/ebios_rm/migrations/0002_remove_ebiosrmstudy_risk_assessments.py
new file mode 100644
index 0000000000..3db7ba7ce2
--- /dev/null
+++ b/backend/ebios_rm/migrations/0002_remove_ebiosrmstudy_risk_assessments.py
@@ -0,0 +1,17 @@
+# Generated by Django 5.1.1 on 2024-12-09 15:43
+
+from django.db import migrations
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('ebios_rm', '0001_initial'),
+    ]
+
+    operations = [
+        migrations.RemoveField(
+            model_name='ebiosrmstudy',
+            name='risk_assessments',
+        ),
+    ]
diff --git a/backend/ebios_rm/models.py b/backend/ebios_rm/models.py
index 1aad3324fe..063af95acd 100644
--- a/backend/ebios_rm/models.py
+++ b/backend/ebios_rm/models.py
@@ -7,7 +7,6 @@
     Asset,
     ComplianceAssessment,
     Qualification,
-    RiskAssessment,
     RiskMatrix,
     Threat,
 )
@@ -49,13 +48,6 @@ class Status(models.TextChoices):
             "Compliance assessments established as security baseline during workshop 1.4"
         ),
     )
-    risk_assessments = models.ManyToManyField(
-        RiskAssessment,
-        blank=True,
-        verbose_name=_("Risk assessments"),
-        related_name="ebios_rm_studies",
-        help_text=_("Risk assessments generated at the end of workshop 4"),
-    )
     reference_entity = models.ForeignKey(
         Entity,
         on_delete=models.PROTECT,
diff --git a/frontend/src/lib/components/Forms/ModelForm/RiskAssessmentForm.svelte b/frontend/src/lib/components/Forms/ModelForm/RiskAssessmentForm.svelte
index e1e4510a69..9c623be769 100644
--- a/frontend/src/lib/components/Forms/ModelForm/RiskAssessmentForm.svelte
+++ b/frontend/src/lib/components/Forms/ModelForm/RiskAssessmentForm.svelte
@@ -110,15 +110,14 @@
 		cacheLock={cacheLocks['observation']}
 		bind:cachedValue={formDataCache['observation']}
 	/>
-	{#if initialData.ebios_rm_studies}
+	{#if initialData.ebios_rm_study}
 		<AutocompleteSelect
 			{form}
-			field="ebios_rm_studies"
-			multiple
-			cacheLock={cacheLocks['ebios_rm_studies']}
-			bind:cachedValue={formDataCache['ebios_rm_studies']}
-			label={m.ebiosRmStudies()}
-			options={getOptions({ objects: model.foreignKeys['ebios_rm_studies'] })}
+			field="ebios_rm_study"
+			cacheLock={cacheLocks['ebios_rm_study']}
+			bind:cachedValue={formDataCache['ebios_rm_study']}
+			label={m.ebiosRmStudy()}
+			options={getOptions({ objects: model.foreignKeys['ebios_rm_study'] })}
 			hidden
 		/>
 	{/if}
diff --git a/frontend/src/lib/utils/crud.ts b/frontend/src/lib/utils/crud.ts
index 18e601d3ce..20035aa2b6 100644
--- a/frontend/src/lib/utils/crud.ts
+++ b/frontend/src/lib/utils/crud.ts
@@ -190,7 +190,7 @@ export const URL_MODEL_MAP: ModelMap = {
 			{ field: 'reviewers', urlModel: 'users', urlParams: 'is_third_party=false' },
 			{ field: 'risk_matrix', urlModel: 'risk-matrices' },
 			{ field: 'risk_scenarios', urlModel: 'risk-scenarios' },
-			{ field: 'ebios_rm_studies', urlModel: 'ebios-rm' }
+			{ field: 'ebios_rm_study', urlModel: 'ebios-rm' }
 		],
 		reverseForeignKeyFields: [{ field: 'risk_assessment', urlModel: 'risk-scenarios' }],
 		selectFields: [{ field: 'status' }],
diff --git a/frontend/src/lib/utils/schemas.ts b/frontend/src/lib/utils/schemas.ts
index 374e2bea7a..7cef358fde 100644
--- a/frontend/src/lib/utils/schemas.ts
+++ b/frontend/src/lib/utils/schemas.ts
@@ -98,7 +98,7 @@ export const RiskAssessmentSchema = z.object({
 	authors: z.array(z.string().optional()).optional(),
 	reviewers: z.array(z.string().optional()).optional(),
 	observation: z.string().optional().nullable(),
-	ebios_rm_studies: z.string().uuid().optional().array().optional()
+	ebios_rm_study: z.string().uuid().optional()
 });
 
 export const ThreatSchema = z.object({
diff --git a/frontend/src/routes/(app)/(internal)/ebios-rm/[id=uuid]/+page.server.ts b/frontend/src/routes/(app)/(internal)/ebios-rm/[id=uuid]/+page.server.ts
index 2a8e773413..bd01382256 100644
--- a/frontend/src/routes/(app)/(internal)/ebios-rm/[id=uuid]/+page.server.ts
+++ b/frontend/src/routes/(app)/(internal)/ebios-rm/[id=uuid]/+page.server.ts
@@ -24,7 +24,7 @@ export const load: PageServerLoad = async ({ params, fetch }) => {
 
     const initialData = {
         risk_matrix: data.risk_matrix.id,
-		ebios_rm_studies: [params.id]
+		ebios_rm_study: params.id
     }
 
     const createSchema = modelSchema('risk-assessments');
diff --git a/frontend/src/routes/(app)/(internal)/ebios-rm/[id=uuid]/workshop-five/risk-analyses/+page.server.ts b/frontend/src/routes/(app)/(internal)/ebios-rm/[id=uuid]/workshop-five/risk-analyses/+page.server.ts
index ad39f045a8..0fac9be876 100644
--- a/frontend/src/routes/(app)/(internal)/ebios-rm/[id=uuid]/workshop-five/risk-analyses/+page.server.ts
+++ b/frontend/src/routes/(app)/(internal)/ebios-rm/[id=uuid]/workshop-five/risk-analyses/+page.server.ts
@@ -23,7 +23,7 @@ export const load: PageServerLoad = async ({ params, fetch }) => {
 	const ebiosMatrixRes = await fetch(`${BASE_API_URL}/ebios-rm/studies/${params.id}/risk-matrix/`);
 	const risk_matrix_id = await ebiosMatrixRes.json().then((res) => res.id);
 	const initialData = {
-		ebios_rm_studies: [params.id],
+		ebios_rm_study: params.id,
 		risk_matrix: risk_matrix_id
 	};
 	const createForm = await superValidate(initialData, zod(createSchema), { errors: false });
@@ -73,8 +73,8 @@ export const load: PageServerLoad = async ({ params, fetch }) => {
 	model['selectOptions'] = selectOptions;
 
 	const endpoint = model.endpointUrl
-		? `${BASE_API_URL}/${model.endpointUrl}?ebios_rm_studies=${params.id}`
-		: `${BASE_API_URL}/${model.urlModel}?ebios_rm_studies=${params.id}`;
+		? `${BASE_API_URL}/${model.endpointUrl}?ebios_rm_study=${params.id}`
+		: `${BASE_API_URL}/${model.urlModel}?ebios_rm_study=${params.id}`;
 	const res = await fetch(endpoint);
 	const data = await res.json().then((res) => res.results);