In 1999, the Department of the Navy (DoN) began a suicide surveillance program using the DoN Suicide Incident Report (DONSIR) to collect data on completed suicides in the Navy and Marine Corps. The DONSIR significantly advances the capability of DoN to track and analyze data on completed suicides over time. The long-term goal of this program is to improve suicide prevention by identifying and modifying military-specific risk factors. A DONSIR has been completed on 98% of the 200 DoN suicides that occurred from 1999 to 2001. Most DoN suicides occurred outside the military work environment and involved the use of a firearm. Most decedents were men, had experienced a recent relationship problem, and did not use any military support services in the 30 days before suicide. Results suggest that the promotion of support services may improve the effectiveness of DoN suicide prevention.