The purpose of this study was to investigate the gender differences in the state of interpersonal needs and psychological health of male and female prison inmates who live in the same prison. The authors conducted in-person interviews with 118 male and 70 female inmates. The results show that women present a better interpersonal state and psychological health than do men. For both genders, the consequences of fulfilling or not fulfilling interpersonal needs-specifically, social loneliness and sexual satisfaction-are associated with psychological health. These findings suggest the importance of the state of prison inmates' interpersonal needs in promoting psychological health in the context of the prison, where these needs are generally difficult to be met. Making contacts possible between male and female inmates who are in the same prison might help them to better fulfill some of their interpersonal needs, especially those related to their sexual lives.