Competences are becoming more and more prominent in undergraduate medical education. Workplace learning is regarded as crucial in competence learning. Assuming that effective learning depends on adequate supervision, feedback and assessment, the authors studied the occurrence of these three variables in relation to a set of clinical competences. They surveyed students at the end of their rotation in surgery, internal medicine or paediatrics asking them to indicate for each competence how often they had received observed and unobserved supervision, the seniority of the person who provided most of their feedback, and whether the competence was addressed in formal assessments. Supervision was found to be scarce and mostly unobserved. Senior staff did not provide much feedback, and assessment mostly targeted patient-related competences. For all variables, the variation between students exceeded that between disciplines. We conclude that conditions for adequate workplace learning are poorly met and that clerkship experiences show huge inter-student variation.