Race and ethnic difference in delinquency are examined using the National Longitudinal Study of Adolescent Health. It is argued that crime theories that attempt to explain race and ethnic differences imply consistent effects for different offenses and common mediating processes. Analyses suggest some degree of group consistency in delinquent behaviors for Mexican-Americans, Puerto Ricans, Native Americans, and some Asian groups, but not for African-Americans. Black youth have higher rates of violent offenses than white youth, lower rates of substance use, and similar rates of property offending. Some variables are consistent mediators while others are not. Crime theories can account for the low rates of delinquency among Asian Americans while theories of violence and substance use are needed to understand differences between black and white youth. The findings are inconsistent with the idea that group differences among youth are due to the socioeconomic status of their families or neighborhoods. The race patterns are also inconsistent with the stereotype of high crime rates in black communities.