Purpose: A consistent finding of research on delinquency has been that gang members show higher levels of delinquent behavior than non-gang members. However, research attempting to understand the mechanisms underlying this finding is lacking. The basic premise of the current article is that the level of organization found in delinquent groups and gangs matters in clarifying the relationship between membership and delinquency. Methods: This article examined the association between organization and delinquency in a sample of 523 self-reported juvenile offenders from a high school survey conducted in the province of Quebec, Canada. Results: The results showed that 1) there is clearly something special about membership in a gang that influences delinquency beyond the more general membership in a delinquent group; 2) the key to understanding finding lies, in part, in the level of organization found in gangs. Organization emerged as the most important factor associated with general delinquency, involvement in violence, and in drug supply offences, significantly (but not completely) reducing the effect of gang membership on delinquency. Conclusions: Even if most delinquent associations show little signs of formal structure and organization, this study demonstrates the importance of organization as a key mechanism to understand the gang effect on delinquency.