diff --git a/hbd/client/plugins/nagios_runner.py b/hbd/client/plugins/nagios_runner.py
index 8a0e37c..d2b0c22 100644
--- a/hbd/client/plugins/nagios_runner.py
+++ b/hbd/client/plugins/nagios_runner.py
@@ -89,12 +89,29 @@ class NagiosRunnerPlugin(MonitorPlugin):
         if not self.commands:
             self.skip_reason = "no commands configured (add nagios_runner.commands to config)"
             return False
-        
+
         self.logger.info(f"Configured to run {len(self.commands)} Nagios plugin(s)")
         for cmd_config in self.commands:
             name = cmd_config.get("name", "unnamed")
             self.logger.info(f"  - {name}: {cmd_config.get('command', 'N/A')}")
-        
+
+        # Validate absolute command paths early
+        for cmd_config in self.commands:
+            name = cmd_config.get("name", "unnamed")
+            command = cmd_config.get("command", "")
+            if not command:
+                continue
+            exe = command.split()[0]
+            if os.path.isabs(exe):
+                if not os.path.isfile(exe):
+                    self.logger.warning(
+                        f"Command '{name}': executable not found: {exe}"
+                    )
+                elif not os.access(exe, os.X_OK):
+                    self.logger.warning(
+                        f"Command '{name}': executable not executable: {exe}"
+                    )
+
         return True
     
     async def _collect_metrics(self) -> Dict[str, Any]:
diff --git a/tests/test_nagios_runner.py b/tests/test_nagios_runner.py
index b2e05c9..8cc6aba 100644
--- a/tests/test_nagios_runner.py
+++ b/tests/test_nagios_runner.py
@@ -60,3 +60,42 @@ def test_negative_returncode_maps_to_unknown():
 
     assert data["t_status_code"] == NAGIOS_UNKNOWN
     assert "signal" in data["t_output"].lower()
+
+
+def test_absolute_path_not_found_warns(caplog):
+    fake_cmd = "/nonexistent_hbc_test_path/check_something"
+    config = {"commands": [{"name": "t", "command": fake_cmd}]}
+    plugin = NagiosRunnerPlugin(config=config)
+
+    with caplog.at_level(logging.WARNING, logger="plugin.nagios_runner"):
+        asyncio.run(plugin.initialize())
+
+    assert any("not found" in r.message for r in caplog.records)
+
+
+def test_absolute_path_not_executable_warns(caplog, tmp_path):
+    non_exec = tmp_path / "check_test"
+    non_exec.write_text("#!/bin/sh\necho OK\n")
+    non_exec.chmod(0o644)  # readable but not executable
+
+    config = {"commands": [{"name": "t", "command": str(non_exec)}]}
+    plugin = NagiosRunnerPlugin(config=config)
+
+    with caplog.at_level(logging.WARNING, logger="plugin.nagios_runner"):
+        asyncio.run(plugin.initialize())
+
+    assert any("not executable" in r.message for r in caplog.records)
+
+
+def test_relative_path_not_checked(caplog):
+    # Relative paths (resolved via PATH) must not generate warnings
+    config = {"commands": [{"name": "t", "command": "echo OK"}]}
+    plugin = NagiosRunnerPlugin(config=config)
+
+    with caplog.at_level(logging.WARNING, logger="plugin.nagios_runner"):
+        asyncio.run(plugin.initialize())
+
+    assert not any(
+        "not found" in r.message or "not executable" in r.message
+        for r in caplog.records
+    )