diff --git a/src/pages/benchmark/forms/basic.tsx b/src/pages/benchmark/forms/basic.tsx
index 32c4024d..c8222b5a 100644
--- a/src/pages/benchmark/forms/basic.tsx
+++ b/src/pages/benchmark/forms/basic.tsx
@@ -1,5 +1,7 @@
+import PluginExtraFields from '@/components/plugin-extra-fields';
 import { modelNameReg, PageAction } from '@/config';
 import { ClusterStatusValueMap } from '@/pages/cluster-management/config';
+import { useQueryClusterList } from '@/pages/cluster-management/services/use-query-cluster-list';
 import { useBenchmarkTargetInstance } from '@/pages/llmodels/hooks/use-run-benchmark';
 import {
   Input as CInput,
@@ -8,7 +10,7 @@ import {
 } from '@gpustack/core-ui';
 import { useIntl } from '@umijs/max';
 import { Form } from 'antd';
-import React, { useEffect } from 'react';
+import React, { useEffect, useMemo } from 'react';
 import { useFormContext } from '../config/form-context';
 import { FormData } from '../config/types';
 import ModelInstanceForm from './model-instance';
@@ -20,31 +22,70 @@ const BasicForm: React.FC = () => {
   const { action, open, clusterList } = useFormContext();
   const { benchmarkTargetInstance } = useBenchmarkTargetInstance();
 
+  // `organization_id` is owned by the create-scope picker slot (admin "All"
+  // view). When a platform admin targets an org (and we're not pre-filling
+  // from a launched instance), fetch *that org's* clusters directly — the
+  // request header carries the chosen org — rather than filtering the
+  // page-level list, which is fetched once and may not include the org's
+  // clusters. The benchmark's owner is derived from the chosen cluster.
+  const scopeOrgId = Form.useWatch('organization_id', form);
+  const orgScoped = scopeOrgId != null && !benchmarkTargetInstance.cluster_id;
+  const {
+    clusterList: scopedClusterList,
+    fetchClusterList: fetchScopedClusters
+  } = useQueryClusterList();
+  // The org-scoped fetch returns clusters *visible* to the org — its own plus
+  // any granted via cluster_access (and the platform principal can see a lot).
+  // A benchmark's owner is the chosen cluster's owner, so keep only clusters
+  // actually owned by the selected org. The owner filter also keeps this
+  // correct if the request header isn't applied (fetch falls back to all).
+  const effectiveClusterList = useMemo(() => {
+    if (!orgScoped) {
+      return clusterList || [];
+    }
+    return (scopedClusterList || []).filter(
+      (item: any) => item.owner_principal_id === scopeOrgId
+    );
+  }, [orgScoped, scopedClusterList, clusterList, scopeOrgId]);
+
   useEffect(() => {
+    if (action === PageAction.CREATE && orgScoped) {
+      fetchScopedClusters({ page: -1 });
+    }
+  }, [scopeOrgId, orgScoped, action]);
+
+  useEffect(() => {
+    if (action !== PageAction.CREATE) {
+      return;
+    }
+    const clusterValue = (item: any) => item?.value ?? item?.id;
     const initClusterId = (list: any[]) => {
       // Find default cluster
       const defaultCluster = list?.find((item) => item.is_default);
       if (defaultCluster) {
-        return defaultCluster.id;
+        return clusterValue(defaultCluster);
       }
 
-      const cluster_id =
-        list?.find((item) => item.state === ClusterStatusValueMap.Ready)?.id ||
-        list?.[0]?.id;
-
-      return cluster_id;
-    };
-    if (
-      clusterList &&
-      clusterList?.length > 0 &&
-      action === PageAction.CREATE
-    ) {
-      form.setFieldValue(
-        'cluster_id',
-        benchmarkTargetInstance.cluster_id || initClusterId(clusterList)
+      const readyCluster = list?.find(
+        (item) => item.state === ClusterStatusValueMap.Ready
       );
+      return clusterValue(readyCluster) ?? clusterValue(list?.[0]);
+    };
+    const current = form.getFieldValue('cluster_id');
+    const stillValid = effectiveClusterList.some(
+      (item: any) => clusterValue(item) === current
+    );
+    if (stillValid) {
+      return;
     }
-  }, [form, action, clusterList, benchmarkTargetInstance]);
+    // Re-pick within the (org-scoped) list. When the chosen org owns no
+    // clusters this resolves to undefined, clearing a stale cross-org cluster
+    // instead of leaving it selected.
+    form.setFieldValue(
+      'cluster_id',
+      benchmarkTargetInstance.cluster_id || initClusterId(effectiveClusterList)
+    );
+  }, [form, action, effectiveClusterList, benchmarkTargetInstance]);
 
   return (
     <>
@@ -67,6 +108,7 @@ const BasicForm: React.FC = () => {
           required
         ></CInput.Input>
       </Form.Item>
+      <PluginExtraFields name="CreateOrgScopeField" context={{ action }} />
       <Form.Item<FormData>
         name="cluster_id"
         rules={[
@@ -78,7 +120,7 @@ const BasicForm: React.FC = () => {
       >
         <SealSelect
           disabled={action === PageAction.EDIT}
-          options={clusterList}
+          options={effectiveClusterList}
           label={intl.formatMessage({ id: 'clusters.title' })}
           required
         ></SealSelect>
diff --git a/src/pages/benchmark/forms/model-instance.tsx b/src/pages/benchmark/forms/model-instance.tsx
index 0ccf1fed..e928ca8a 100644
--- a/src/pages/benchmark/forms/model-instance.tsx
+++ b/src/pages/benchmark/forms/model-instance.tsx
@@ -10,7 +10,7 @@ import { useQueryModelList } from '@/pages/llmodels/services/use-query-model-lis
 import { Cascader as SealCascader, useAppUtils } from '@gpustack/core-ui';
 import { useIntl } from '@umijs/max';
 import { Form, Tooltip } from 'antd';
-import React, { useEffect } from 'react';
+import React, { useEffect, useRef } from 'react';
 import { useFormContext } from '../config/form-context';
 import { FormData } from '../config/types';
 
@@ -45,6 +45,11 @@ const ModelInstanceForm: React.FC = () => {
   const form = Form.useFormInstance();
   const { getRuleMessage } = useAppUtils();
   const { action, open } = useFormContext();
+  // Owned by the create-scope picker slot (admin "All" view). The model list
+  // is tenant-scoped by the request header, so refetch it when the org
+  // changes so only the chosen org's models/instances are offered.
+  const scopeOrgId = Form.useWatch('organization_id', form);
+  const prevScopeRef = useRef<number | null | undefined>(undefined);
   const [modelList, setModelList] = React.useState<any[]>([]);
   const {
     loading: modelLoading,
@@ -158,14 +163,29 @@ const ModelInstanceForm: React.FC = () => {
 
   useEffect(() => {
     if (open && action === PageAction.CREATE) {
+      // On a genuine org change, clear the stale (possibly cross-org) target
+      // so the refetched list re-selects within the new org.
+      if (
+        prevScopeRef.current !== undefined &&
+        prevScopeRef.current !== scopeOrgId
+      ) {
+        form.setFieldsValue({
+          model_name: undefined,
+          model_id: undefined,
+          model_instance_name: undefined,
+          model_instance: undefined
+        });
+      }
+      prevScopeRef.current = scopeOrgId;
       initModelInstance();
     }
     if (!open) {
+      prevScopeRef.current = undefined;
       cancelModelRequest();
       cancelInstanceRequest();
       clearBenchmarkTargetInstance();
     }
-  }, [open, benchmarkTargetInstance, action]);
+  }, [open, benchmarkTargetInstance, action, scopeOrgId]);
 
   return (
     <Form.Item<FormData>