Background: Although clinical supervision is considered to be a major component of the development and maintenance of psychotherapeutic competencies, and despite an increase in supervision research, the empirical evidence on the topic remains sparse. Methods: Because most previous reviews lack methodological rigor, we aimed to review the status and quality of the empirical literature on clinical supervision, and to provide suggestions for future research. MEDLINE, PsycInfo and the Web of Science Core Collection were searched and the review was conducted according to current guidelines. From the review results, we derived suggestions for future research on clinical supervision. Results: The systematic literature search identified 19 publications from 15 empirical studies. Taking into account the review results, the following suggestions for further research emerged: Supervision research would benefit from proper descriptions of how studies are conducted according to current guidelines, more methodologically rigorous empirical studies, the investigation of active supervision interventions, from taking diverse outcome domains into account, and from investigating supervision from a meta-theoretical perspective. Conclusions: In all, the systematic review supported the notion that supervision research often lags behind psychotherapy research in general. Still, the results offer detailed starting points for further supervision research.