The majority of incarcerated adults are parents. While in prison, most parents maintain at least some contact with their families. A positive connection with family during imprisonment is hypothesized to improve long-term success after release. One way in which departments of corrections attempt to facilitate positive connections with family is through prison-based parenting programs. One such program, developed in collaboration with the Oregon Department of Corrections, is the cognitive-behavioral parent management training program Parenting Inside Out (PIO). Outcomes due to PIO were examined within the context of a randomized controlled trial. Incarcerated parents from all correctional facilities in the state of Oregon were recruited to participate, and eligible parents who consented (N = 359) were transferred to participating releasing institutions. After initial assessment, parents were randomized to condition (i.e., PIO “intervention” condition or services-as-usual “control” condition) and then followed through the remainder of their prison sentences and to one year after release. Intervention condition participants were offered PIO prior to their release. Outcomes favoring participants in the intervention condition were found in areas of importance to parents and their children and families and to public health and safety at large, including a decreased likelihood of problems related to substance use and of engaging in criminal behavior during the first six months following release as well as a decreased likelihood of being arrested by police during the first year following release. The implications of the findings are discussed, including the critical need for scientifically rigorous research on multi-component parenting programs delivered during the reentry period.