Data were obtained from a variety of official military records. Some discrepancies in black-white incarceration rates are present in both services but of smaller magnitude in the Marine Corps than in the Navy. In both cases a very high relative incarceration rate was found for blacks with a high school education who are older and still on the bottom of the rank structure. Due to prejudice in the civilian world, lower ranking, older blacks trapped by the stress and frustration of being unable to advance in rank and pay are less likely than whites of similar education and skill levels to leave the service. Such blacks are thus more likely to be incarcerated than to leave the service. Even when age, education, and pay grade were controlled, white prisoners proportionately outnumbered blacks in the unauthorized absences category and black confinees were disproportionately concentrated in the major military offense category (largely violent crimes, such as murder, rape, robbery, and assault). This finding holds for both sea services. This racial differential had been discovered previously in offense patterns among civilian offenders. Once type of offense is taken into account, no statistically significant black-white differences can be seen with regard to sentence length (due, perhaps, to the high degree of standardization of sentencing criteria and their application). Overall, no evidence was found of institutional discrimination against either racial group. Over 160 references, an index, and tabular data are provided.