After reviewing the relevant literature on the differential legal treatment of American Indians, the authors examine differences between Indians and whites for two adjudication outcomes within separate felony crime categories: sentence received for new State prison admissions and percent of sentence served for new State prison releases. The analysis was based on State prison admission and release data from the five States. In the aggregate, the data show that American Indians received longer sentences more often for offenses such as robbery and burglary, as well as for drug trafficking and public order offenses, and whites more often received longer sentences for larceny. The results for homicide, sexual assault, and assault were more closely matched. These patterns, however, varied greatly by crime and State. The greater leniency for American Indians in some cases may be consistent with certain theoretical propositions presented in the literature. Indian-on-Indian crimes may yield more lenient sentences for the Indian offenders; whereas, Indian-on-white crimes may produce harsher sentences for the Indian offenders. Compared to white inmates, American Indian inmates showed a clear pattern of serving higher proportions of their sentences in every State except California for every crime. Overall, results suggest the possibility that at least some degree of discriminatory behavior by the criminal justice system exists against American Indians. The extent and nature of this discrimination is still unclear, however, and more research is needed. 5 tables and 3 notes