The study of 153 women inmates was based on field observations, interviews with the inmates, and examination of the institutional case records. Data were gathered over an 8-month period. Two contrasting groups emerged as a result: those who did not identify with the prison life and kept to themselves, and those who were active in institutional programs and achieved a high degree of contact with other inmates. The seven women perceived as leaders within the informal social structure of the prison belonged to the latter group. In addition, they displayed characteristics similar to the men found to be leaders in other studies of male inmates. The women were convicted of traditionally masculine property offenses (burglary and robbery), were outspoken, and were even able to bring about institutional changes which gave all the inmates more freedom of interaction. They were also able to defend themselves physically, and played the dominant male role in homosexual relationships. Statistical data, a review of the literature, and 20 references are included.