diff --git a/cecli/commands/__init__.py b/cecli/commands/__init__.py
index 8095f367e9e..7671804f33b 100644
--- a/cecli/commands/__init__.py
+++ b/cecli/commands/__init__.py
@@ -8,6 +8,7 @@
 from .add import AddCommand
 from .agent import AgentCommand
 from .agent_model import AgentModelCommand
+from .agent_tree import AgentTreeCommand
 from .architect import ArchitectCommand
 from .ask import AskCommand
 from .clear import ClearCommand
@@ -94,6 +95,7 @@
 CommandRegistry.register(AddCommand)
 CommandRegistry.register(AgentCommand)
 CommandRegistry.register(AgentModelCommand)
+CommandRegistry.register(AgentTreeCommand)
 CommandRegistry.register(ArchitectCommand)
 CommandRegistry.register(AskCommand)
 CommandRegistry.register(ClearCommand)
@@ -169,6 +171,7 @@
     "AddCommand",
     "AgentCommand",
     "AgentModelCommand",
+    "AgentTreeCommand",
     "ArchitectCommand",
     "AskCommand",
     "BaseCommand",
diff --git a/cecli/commands/agent_tree.py b/cecli/commands/agent_tree.py
new file mode 100644
index 00000000000..9e8cd96dfdc
--- /dev/null
+++ b/cecli/commands/agent_tree.py
@@ -0,0 +1,95 @@
+from typing import List
+
+from cecli.commands.utils.base_command import BaseCommand
+from cecli.helpers.agents.service import AgentService, SubAgentInfo, SubAgentStatus
+
+
+class TreeNode:
+    """A node in the agent hierarchy tree."""
+
+    def __init__(self, agent_info: SubAgentInfo):
+        self.agent_info = agent_info
+        self.children: List[TreeNode] = []
+
+    def add_child(self, child_node: "TreeNode"):
+        self.children.append(child_node)
+
+
+class AgentTreeCommand(BaseCommand):
+    """Command to display the hierarchy of active agents."""
+
+    NORM_NAME = "agent-tree"
+    DESCRIPTION = "Display the hierarchy of active agents."
+
+    @classmethod
+    async def execute(cls, io, coder, args, **kwargs):
+        """Execute the /agent-tree command."""
+        agent_service = AgentService.get_instance(coder)
+        if not agent_service:
+            io.tool_output("Agent service not available.")
+            return
+
+        # Collect all agents: primary coder + sub-agents from sub_agents dict
+        all_infos: List[SubAgentInfo] = []
+
+        # Primary agent as a synthetic SubAgentInfo
+        primary_coder = agent_service.coder
+        primary_info = SubAgentInfo(
+            name="primary",
+            coder=primary_coder,
+            parent_uuid=str(primary_coder.parent_uuid or ""),
+            status=SubAgentStatus.RUNNING,
+        )
+        all_infos.append(primary_info)
+
+        # Sub-agents from the service's sub_agents dict
+        for info in agent_service.sub_agents.values():
+            if info and info.coder:
+                all_infos.append(info)
+
+        if len(all_infos) <= 1:
+            io.tool_output("No active sub-agents found.")
+            return
+
+        root_nodes = cls._build_tree(all_infos)
+        tree_output = cls._render_tree(root_nodes)
+        io.tool_output(tree_output)
+
+    @classmethod
+    def _build_tree(cls, all_agents: List[SubAgentInfo]) -> List[TreeNode]:
+        """Build the agent tree from a flat list of agents."""
+        nodes = {str(agent.coder.uuid): TreeNode(agent) for agent in all_agents}
+        root_nodes = []
+
+        for agent in all_agents:
+            parent_uuid = str(agent.coder.parent_uuid)
+            if parent_uuid and parent_uuid in nodes:
+                parent_node = nodes[parent_uuid]
+                child_node = nodes[str(agent.coder.uuid)]
+                parent_node.add_child(child_node)
+            else:
+                root_nodes.append(nodes[str(agent.coder.uuid)])
+
+        return root_nodes
+
+    @classmethod
+    def _render_tree(cls, nodes: List[TreeNode]) -> str:
+        """Render the agent tree to a string."""
+        output = []
+
+        def render_node(node: TreeNode, prefix: str = "", is_last: bool = True):
+            connector = "└── " if is_last else "├── "
+            output.append(
+                f"{prefix}{connector}{node.agent_info.name}"
+                f" ({node.agent_info.status.value})"
+                f" - {str(node.agent_info.coder.uuid)}"
+            )
+
+            child_prefix = prefix + ("    " if is_last else "│   ")
+            for i, child in enumerate(node.children):
+                render_node(child, child_prefix, i == len(node.children) - 1)
+
+        for i, node in enumerate(nodes):
+            render_node(node, is_last=i == len(nodes) - 1)
+
+        return "\n".join(output)