The findings show that the role of gender in predicting nonphysical and physical peer victimization is complex. Gender alone is not a direct explanation of peer victimization. Apparently, the more important variables related to peer victimization are individual and situational characteristics as well as protective factors that interact with gender in producing differences in the victimization experiences of girls and boys. Boys, but not girls, who showed increases in social competence or behavioral problems tended to be at greater risk for physical victimization; on the other hand, girls, but not boys, who showed increases in emotional problems were at greater risk for peer physical victimization. Few predictors of increases in nonphysical victimization were found. There is a need to examine changes in both levels and predictors of peer victimization as children age and progress through elementary school. These findings are from the W.I.T.S. Longitudinal Study being conducted by the University of Victoria (British Columbia, Canada). Of the initial sample of 432 children, 397 participated at the third wave of data collection. Forty-four classrooms in 17 elementary schools in a local school district are participating in the study. At three intervals, the study has measured children's social competence, emotional problems, behavioral problems, prosocial acts, nonphysical peer victimization, and peer physical victimization. 2 tables and 39 references