The purpose of the study was to investigate sexual harassment experiences of junior high school students with and without mental retardation (MR). Subjects consisted of 1085 regular class students and 564 MR students (either in the resource room or self-contained class). A research-designed instrument was employed to cull both active and passive harassment behaviors. Results indicated (a) in the active sexual harassment, regular class students were more likely to harass others than the MR group were; for both groups, victims were likely to be schoolmates of the opposite sex; both groups offended other more frequently on campus than other places. As a whole, boys had far more active sexual harassment behaviors than girls did. Active sexual harassment behaviors were also associated with living location, family structure, parents' marital status, and father's education level. And (b) in terms of passive sexual harassment, compared to their regular peers, the MR groups were more likely to be sexually barassed and were more frequently offended by strangers. As a whole, girls were more likely to be victims of sexual harassment. Other factors that affected passive sexual hehaviors included the family structure, parents' marital status, the living location, and mother's educational level.