Evidence from several prison systems indicates that gang-affiliated inmates are over-represented in restrictive housing. It is not clear whether this circumstance is due to their need for protection, discipline for misconduct, or the perceived threat associated with their gang membership. A review of the relevant evidence suggests that the justification for the large-scale placement of gang-affiliated inmates in restrictive housing is limited; however, the available evidence suggests that restrictive housing may reduce inmate rule violations. A positive move toward jointly reducing the influence of gangs in prisons and the over-use of restrictive housing consists of a system that specifies the incentive-based steps that can move an inmate in restrictive housing into the prison general population. Another promising effort is to provide treatment-based efforts that promote renouncement of gang ties. Such programs, however, must be accompanied by rigorous, scientific evaluation. Such an effort can be facilitated by establishing mutually beneficial researcher-practitioner partnerships that lead to the design, implementation, and evaluation of promising efforts to reduce the influence of gangs in prisons. Using research to develop data-driven policies will facilitate better-informed decisions about the use of restrictive housing for gang-affiliated inmates.