Background: Supervision is a common feature across post-graduate medical education contexts. Feedback is one of the mechanisms through which supervision is thought to achieve desirable behavioural and attitudinal change in junior doctors. Objectives: To synthesise what is known about effective feedback in clinical supervision. Based on this, practical recommendations will be made to support supervisors and supervisees to ensure that feedback messages become more than just the tired old proverbial ‘sandwich’. Methods: Systematic review (Weallans et al., 2021) following the Preferred Reporting Systematic Reviews and Meta-Analyses (PRISMA) process, including quality assessment of the available empirical literature. In addition, qualitative content analysis of the theoretical literature was completed to identify common principles of effective feedback and to explore the level of empirical support for these. Findings: There is very limited empirical support for models of feedback in clinical supervision. Reassuringly there is general consensus around common principles and empirical support for these. Effective feedback in clinical supervision is more than the delivery of a wellconstructed feedback message. Effective feedback requires the establishment and maintenance of a collaborative relationship with shared goals, repeated observation of practice and linking feedback message to a plan for action. Conclusion: While the empirical evidence is limited, there is a general consensus about how supervisors can achieve effective feedback in clinical supervision.