Enlisted grade prisoners in Naval and Marine Corps confinement institutions are studied for the last quarter of 1972, with 93 percent of the total Navy prisoner population and 100 percent of Marine Corps prisoners represented. For comparison, data on all Navy and Marine Corps personnel not incarcerated during the last quarter of 1972 were collected. Incarceration rates for blacks in the Navy and Marine Corps are consistently higher than those for whites, even when age, pay grade, and education are taken into account. This would seem to indicate that either blacks commit more crimes than whites (an argument for which no convincing logic exists) or that some selection process is operating whereby blacks are more likely to get into the military criminal justice system and hence, almost by default, are more likely to be incarcerated. It is known, for example, that in the civilian population blacks have higher probabilities of arrest and are more closely scrutinized by social control agents than whites; perhaps this condition is reflected in the military. Often seen in a nontechnological setting like the Marine Corps, is an influx of minority group members who find that their lack of formal education does not block their entrance into the military occupational structure. Unfortunately, however, their low level of educational achievement does slow their advancement in the occupational structure, and such people tend to remain in the lower rank and pay-grade positions for a longer than average time period. Older, low ranking personnel have probably encountered situational difficulties. The extended time in grade increases the probability that minority soldiers will violate rules and acquire 'problem soldier' status, which is often a self-fulfilling prophecy. Whatever the case, the finding of race differentials in incarceration is significant enough to suggest a need for research on the military apprehension and arrest system and the procedures for bringing charges. Tables and 10 notes are provided. (Author abstract modified)