The study of prison gangs is particularly important given the scope of incarceration and gang involvement. This chapter describes the contemporary literature on gangs in the correctional environment and how prison gangs differ from street gangs. It explores the prevalence and nature of gang membership in prisons, and describes the development of prison gangs and pathways to the prison gang life. The chapter talks about the nature of gang‐involved prison behavior, including programming modalities designed to address the needs of this population. Many correctional officials have developed partnerships with local law enforcement in order to develop a more comprehensive picture of gangs on the street and to aid in solving crimes in the community. The chapter concludes with a discussion on the unique needs of gang‐involved prisoners and parolees and ideas for new avenues for research in this important topical area.