The questionnaire, which consisted of 18 questions, contained open-ended and closed-ended questions designed to determine why prison gang members left their gangs. The average age of defected gang members was 32.75, compared to 32.80 for active gang members. In terms of gang affiliation, 50 percent (n=24) were former members of the Mexican Mafia, followed by the Aryan Brotherhood of Texas (n=11). Overall, the data show that less than 5 percent of prison gang members defected from their gangs. No one prison gang had significantly more or less defectors. All respondents reported no previous participation in street gangs; their active participation in prison gangs before defection was 3.36 years. Prison gangs are organized along paramilitary lines, and the majority of respondents never held any rank beyond that of "soldier." Additional analyses revealed that only 12 of the respondents admitted to having committed gang-related violence. Findings show that the single most important reason for leaving the gang was loss of interest in the gang (n=10), followed by refusing to carry out a "hit" on a non-gang member (n=9). Other reasons included disagreeing with the direction in which the gang was going (n=7), refusal to carry out a "hit" on a fellow gang member (n=6), violating a gang rule (n=5), "growing out" of it (n=5), informing prison officials about gang business (n=4), and refusing to engage in gang crime (n=2). Given that the commitment to the prison gang is expected to last a lifetime, with death being the punishment for defection, it is surprising that most of the respondents left their gangs for the relatively inane reason of having lost interest in it. Additional research is necessary to determine what "losing interest" in the gang means to defectors. 1 table and 34 references