In the past, it was assumed that peer delinquency and gang membership were identical in concepts and measures. Using a latent structure analysis, this study assessed the distinction between peer delinquency and gang membership. Respondents for the study were asked to self-report involvement in a wide range of delinquent activity. Four measures of self-reported delinquency were selected for analysis. The analysis found that both peer delinquency and gang membership were significant predictors of self-reported delinquency. In addition, the latent variable analyses found that neither gang membership nor peer delinquency might be considered as apart of the same underlying construct as self-reported delinquency. It was suggested that additional causes of delinquency be considered. Evidence was found to suggest that both the social control theory and social learning theory provided concepts useful in explaining delinquency. Measures of belief and attachment were inversely correlated with self-reported delinquency, as was a measure of commitment; in particular, academic performance was a relatively strong, negative correlate of self-reported delinquency. Tables and references