diff --git a/erpnext/crm/doctype/opportunity/opportunity.py b/erpnext/crm/doctype/opportunity/opportunity.py
index 98b849a94f6..a018dc1f1fb 100644
--- a/erpnext/crm/doctype/opportunity/opportunity.py
+++ b/erpnext/crm/doctype/opportunity/opportunity.py
@@ -133,6 +133,7 @@ class Opportunity(TransactionBase, CRMNote):
 		self.validate_uom_is_integer("uom", "qty")
 		self.validate_cust_name()
 		self.validate_party()
+		self.validate_party_specific_items()
 		self.map_fields()
 		self.validate_qty()
 		self.set_exchange_rate()
@@ -145,6 +146,32 @@ class Opportunity(TransactionBase, CRMNote):
 	def on_update(self):
 		self.update_prospect()
 
+	def validate_party_specific_items(self):
+		if self.opportunity_from != "Customer" or not self.party_name:
+			return
+
+		from erpnext.selling.doctype.party_specific_item.party_specific_item import get_party_specific_items
+
+		allowed_values = get_party_specific_items(self.party_name)
+		if not allowed_values:
+			return
+
+		rows = [row for row in self.get("items") if row.item_code]
+		allowed_items = frappe.get_all(
+			"Item",
+			filters=[["name", "in", list({row.item_code for row in rows})]]
+			+ [[field, "in", values] for field, values in allowed_values.items()],
+			pluck="name",
+		)
+		for row in rows:
+			if row.item_code not in allowed_items:
+				frappe.throw(
+					_("Row {0}: Item {1} is not allowed for {2} {3}.").format(
+						row.idx, frappe.bold(row.item_code), _("Customer"), frappe.bold(self.party_name)
+					),
+					title=_("Item Restricted for Party"),
+				)
+
 	def validate_qty(self):
 		for item in self.items:
 			if flt(item.qty) <= 0:
diff --git a/erpnext/selling/doctype/party_specific_item/test_party_specific_item.py b/erpnext/selling/doctype/party_specific_item/test_party_specific_item.py
index 136bc8fbb20..734951e97d4 100644
--- a/erpnext/selling/doctype/party_specific_item/test_party_specific_item.py
+++ b/erpnext/selling/doctype/party_specific_item/test_party_specific_item.py
@@ -94,3 +94,22 @@ class TestPartySpecificItem(FrappeTestCase):
 		standalone_note = frappe.copy_doc(credit_note)
 		standalone_note.return_against = None
 		self.assertRaisesRegex(frappe.ValidationError, "is not allowed for", standalone_note.insert)
+
+	def test_opportunity_enforces_party_rules(self):
+		from erpnext.crm.doctype.opportunity.test_opportunity import make_opportunity
+
+		create_party_specific_item(
+			party_type="Customer",
+			party="_Test Customer 1",
+			restrict_based_on="Item",
+			based_on_value="_Test Item Home Desktop 100",
+		)
+		make_opportunity(with_items=1, customer="_Test Customer 1", item_code="_Test Item Home Desktop 100")
+		self.assertRaisesRegex(
+			frappe.ValidationError,
+			"is not allowed for Customer",
+			make_opportunity,
+			with_items=1,
+			customer="_Test Customer 1",
+			item_code="_Test Item",
+		)