The U.S. Department of Defense desires to reduce the impact of coronary atherosclerosis on its active duty, retired, and dependent populations. Electron beam computed tomography (EBCT) is currently the best way to noninvasively image the coronary arteries directly. Between August 1997 and February 1999, a total of 3,263 patients were scanned by EBCT in the Radiology Department at Walter Reed Army Medical Center. Scans were performed on 2,415 men (74%) and 848 women (26%). The most common age group was 50 to 54 years (25%). Coronary calcification was found in approximately half of the patients (46%), and the magnitude of the score was strongly associated with age and male gender. Average scores increased exponentially with age, doubling every 7 years. In men, average scores ranged from 17 units in those aged 35 to 39 years to 842 in those older than 70 years old. In women, average scores ranged from 1 in those 35 to 39 years to 162 in those older than 70 years. Significant numbers of patients fell into the high-risk categories, with 8% of men in their 40s, 20% of men in their 50s, 33% of men in their 60s, and 49% of men in their 70s with high scores. Scores of more than 400 units were seen in 368 patients (8%) overall. There is a large amount of coronary calcium present in military personnel and their dependents, in patterns that are consistent with previous studies. Many patients had very high scores that are consistent with advanced coronary artery disease. EBCT should play a central role in the identification of occult calcific atherosclerosis of the coronary arteries in military, retired, and dependent patients.