PURPOSE OF REVIEW: Considering international diversity in the implementation of mental health peer support and an increasing research interest in peer support work (PSW), this review focuses on priorities in current research and practice. With grassroots in informal services for people with mental health problems, peer support has been strengthened by the recovery paradigm in mental health policy, and there are steps towards integration in statutory services. RECENT FINDINGS: Current issues include benefits of peer support, its efficacy and effectiveness. The value of peer support in formal and informal settings is discussed, and organizational change processes and the challenges in peer support implementation are discussed. Recent studies have identified the need for a clarification of roles, competencies and job structure and for adequate training and supervision. Along with reported benefits for consumer and PSW involvement in care revealed by mixed method studies, destigmatization at the personal and system level is a crucial PSW component. SUMMARY: Various types of peer support merit further evaluation. Assessing the impact of peer support on service users, peer providers and organizations require complex intervention studies, using mixed methods designs with qualitative exploration of underlying processes and experiences to complement high-quality controlled trials.