Incident reporting systems and root cause analyses remain the main mechanisms by which adverse events are identified and reviewed. This study sought to determine whether more localized, unit-based incident reporting systems might provide better insight into how patient safety incidents vary across hospital units and services than hospital or national level reporting systems. While similar safety issues and root causes were identified across all units and services, medication safety issues were more common on internal medicine and surgical units. On the other hand, collaboration issues were more frequent in emergency medicine units. These findings suggest that localized safety reporting systems might provide information that could promote improvement efforts.