Peers are an important influence on college students' substance use and other risky behaviors. Students at a midsize state university in the Midwest (N = 489) completed an online survey assessing their alcohol risk, marijuana risk, engagement in antisocial behaviors, and social network characteristics. Respondent problem behaviors were associated with friend substance use and friend antisocial behavior. Friends that were seen as more emotionally supportive and friends made during college shared more similar risks. Year in college and gender of participant demonstrated mixed effects. Implications for peer-focused alcohol and other risk behavior interventions are discussed.