This study investigated differences in aggressive attitudes, academic achievement and discipline referrals between bullies and non-bullies in a sample of 261 6th and 7th grade students over a two-year period. Through the use of a peer nomination survey, 16 students were identified as bullies both years (persistent) and 21 were identified only in the first year (desistent). Across all students, aggressive attitudes were associated with poorer grades and more discipline infractions, but persistent bullies had the most aggressive attitudes and were more likely to get into trouble in school than desistent bullies or control students. Desistent bullies were more similar to control students than persistent bullies. These findings support the need to differentiate among middle school bullies and to focus attention on the aggressive attitudes of persistent bullies. (Contains 1 table.)