diff --git a/ui/src/components/IssueProperties.test.tsx b/ui/src/components/IssueProperties.test.tsx
index f795978457c..81da9782871 100644
--- a/ui/src/components/IssueProperties.test.tsx
+++ b/ui/src/components/IssueProperties.test.tsx
@@ -722,6 +722,70 @@ describe("IssueProperties", () => {
     act(() => root.unmount());
   });
 
+  it("collapses long blocked-by and sub-task lists until the more button is clicked", async () => {
+    const blockedBy = Array.from({ length: 7 }, (_, index) => ({
+      id: `blocker-${index + 1}`,
+      identifier: `BLOCK-${index + 1}`,
+      title: `Blocker ${index + 1}`,
+      status: "todo",
+      priority: "medium",
+      assigneeAgentId: null,
+      assigneeUserId: null,
+    })) as NonNullable<Issue["blockedBy"]>;
+    const childIssues = Array.from({ length: 7 }, (_, index) => createIssue({
+      id: `child-${index + 1}`,
+      identifier: `SUB-${index + 1}`,
+      title: `Sub-task ${index + 1}`,
+    }));
+    const root = renderProperties(container, {
+      issue: createIssue({ blockedBy }),
+      childIssues,
+      onUpdate: vi.fn(),
+      inline: true,
+    });
+    await flush();
+
+    expect(container.textContent).toContain("BLOCK-5");
+    expect(container.textContent).not.toContain("BLOCK-6");
+    expect(container.textContent).toContain("SUB-5");
+    expect(container.textContent).not.toContain("SUB-6");
+    expect(
+      Array.from(container.querySelectorAll("button")).filter((button) =>
+        button.textContent?.trim() === "and 2 more...",
+      ),
+    ).toHaveLength(2);
+
+    const expandBlockedBy = Array.from(container.querySelectorAll("button")).find((button) =>
+      button.textContent?.trim() === "and 2 more...",
+    );
+    expect(expandBlockedBy).not.toBeUndefined();
+    await act(async () => {
+      expandBlockedBy!.dispatchEvent(new MouseEvent("click", { bubbles: true }));
+    });
+
+    expect(container.textContent).toContain("BLOCK-6");
+    expect(container.textContent).toContain("BLOCK-7");
+    expect(container.textContent).not.toContain("SUB-6");
+
+    const expandSubTasks = Array.from(container.querySelectorAll("button")).find((button) =>
+      button.textContent?.trim() === "and 2 more...",
+    );
+    expect(expandSubTasks).not.toBeUndefined();
+    await act(async () => {
+      expandSubTasks!.dispatchEvent(new MouseEvent("click", { bubbles: true }));
+    });
+
+    expect(container.textContent).toContain("SUB-6");
+    expect(container.textContent).toContain("SUB-7");
+    expect(
+      Array.from(container.querySelectorAll("button")).filter((button) =>
+        button.textContent?.trim() === "and 2 more...",
+      ),
+    ).toHaveLength(0);
+
+    act(() => root.unmount());
+  });
+
   it("shows a green service link above the workspace row for a live non-main workspace", async () => {
     mockProjectsApi.list.mockResolvedValue([createProject()]);
     const serviceUrl = "http://127.0.0.1:62475";
diff --git a/ui/src/components/IssueProperties.tsx b/ui/src/components/IssueProperties.tsx
index a3d419255b6..b610c5289f0 100644
--- a/ui/src/components/IssueProperties.tsx
+++ b/ui/src/components/IssueProperties.tsx
@@ -154,6 +154,7 @@ interface IssuePropertiesProps {
 }
 
 const ISSUE_BLOCKER_SEARCH_LIMIT = 50;
+const ISSUE_PROPERTY_RELATION_PREVIEW_COUNT = 5;
 
 function PropertyRow({ label, children }: { label: string; children: React.ReactNode }) {
   return (
@@ -321,6 +322,25 @@ function RemovableIssueReferencePill({
   );
 }
 
+function ExpandRelationListButton({
+  hiddenCount,
+  onClick,
+}: {
+  hiddenCount: number;
+  onClick: () => void;
+}) {
+  if (hiddenCount <= 0) return null;
+  return (
+    <button
+      type="button"
+      className="inline-flex items-center gap-1 rounded-full border border-border px-2 py-0.5 text-xs text-muted-foreground transition-colors hover:bg-accent/50 hover:text-foreground"
+      onClick={onClick}
+    >
+      and {hiddenCount} more...
+    </button>
+  );
+}
+
 /** Renders a Popover on desktop, or an inline collapsible section on mobile (inline mode). */
 function PropertyPicker({
   inline,
@@ -408,6 +428,8 @@ export function IssueProperties({
   const [projectSearch, setProjectSearch] = useState("");
   const [blockedByOpen, setBlockedByOpen] = useState(false);
   const [blockedBySearch, setBlockedBySearch] = useState("");
+  const [blockedByExpanded, setBlockedByExpanded] = useState(false);
+  const [subTasksExpanded, setSubTasksExpanded] = useState(false);
   const [parentOpen, setParentOpen] = useState(false);
   const [parentSearch, setParentSearch] = useState("");
   const [reviewersOpen, setReviewersOpen] = useState(false);
@@ -1673,6 +1695,15 @@ export function IssueProperties({
   );
 
   const blockedByIds = issue.blockedBy?.map((relation) => relation.id) ?? [];
+  const blockedByRelations = issue.blockedBy ?? [];
+  const visibleBlockedByRelations = blockedByExpanded
+    ? blockedByRelations
+    : blockedByRelations.slice(0, ISSUE_PROPERTY_RELATION_PREVIEW_COUNT);
+  const hiddenBlockedByCount = blockedByRelations.length - visibleBlockedByRelations.length;
+  const visibleChildIssues = subTasksExpanded
+    ? childIssues
+    : childIssues.slice(0, ISSUE_PROPERTY_RELATION_PREVIEW_COUNT);
+  const hiddenChildIssueCount = childIssues.length - visibleChildIssues.length;
   const descendantIssueIds = useMemo(() => {
     if (!allIssues?.length) return new Set<string>();
     const childrenByParentId = new Map<string, string[]>();
@@ -1985,9 +2016,13 @@ export function IssueProperties({
         {inline ? (
           <div>
             <PropertyRow label="Blocked by">
-              {(issue.blockedBy ?? []).map((relation) => (
+              {visibleBlockedByRelations.map((relation) => (
                 <RemovableIssueReferencePill key={relation.id} issue={relation} onRemove={removeBlockedBy} />
               ))}
+              <ExpandRelationListButton
+                hiddenCount={hiddenBlockedByCount}
+                onClick={() => setBlockedByExpanded(true)}
+              />
               {renderAddBlockedByButton(() => setBlockedByOpen((open) => !open))}
             </PropertyRow>
             {blockedByOpen && (
@@ -1998,9 +2033,13 @@ export function IssueProperties({
           </div>
         ) : (
           <PropertyRow label="Blocked by">
-            {(issue.blockedBy ?? []).map((relation) => (
+            {visibleBlockedByRelations.map((relation) => (
               <RemovableIssueReferencePill key={relation.id} issue={relation} onRemove={removeBlockedBy} />
             ))}
+            <ExpandRelationListButton
+              hiddenCount={hiddenBlockedByCount}
+              onClick={() => setBlockedByExpanded(true)}
+            />
             <Popover
               open={blockedByOpen}
               onOpenChange={(open) => {
@@ -2031,10 +2070,14 @@ export function IssueProperties({
         <PropertyRow label="Sub-tasks">
           <div className="flex flex-wrap items-center gap-1.5">
             {childIssues.length > 0
-              ? childIssues.map((child) => (
+              ? visibleChildIssues.map((child) => (
                 <IssueReferencePill key={child.id} issue={child} />
               ))
               : null}
+            <ExpandRelationListButton
+              hiddenCount={hiddenChildIssueCount}
+              onClick={() => setSubTasksExpanded(true)}
+            />
             {onAddSubIssue ? (
               <button
                 type="button"