Even though it has been demonstrated that peer support contributes to positive outcomes for service users, organizational implementation issues remain. The aim of the current study was to examine an implementation of peer support from the perspective of managers in order to develop knowledge of factors influencing sustainability of this initiative. Eighteen managers were interviewed in connection with the introduction of peer support in sixteen mental health settings. Interviews were analyzed utilizing inductive and deductive approaches. The results suggested that managers were predominantly positive in their evaluation of peer support as a recovery-oriented addition to their services, but noted developmental issues regarding role, professional identity, supervision and financing in relation to other traditional personnel. The involvement of the user movement, especially with regard to training and supervision helped prepare staff and support peer workers, yet there was some apprehension attached to the critical scrutiny that this `outsider’ perspective might imply. The results confirm previously noted uncertainties regarding peer support as an integrated component of mental health systems and illuminate a number of culturally conditioned challenges that may hamper peer support from being implemented with the same approach as other interventions. In response, the present study suggests a number of focus areas that should be attended to in future implementation efforts, including issues related to staff roles, power dynamics, connection to the user movement and reconsideration of the value of experience-based knowledge. In the Swedish context, a government level commitment was identified as critical to ensure stable funding.