Background: As the communication competencies of physicians are crucial for providing optimal patient care, their assessment in the context of the high-stakes Objective Structured Clinical Examination (OSCE) is of paramount importance. Despite abundant literature on the topic, evidence-based recommendations for the assessment of communication competencies in high stakes OSCEs are scarce. As part of a national project to improve communication-competencies assessments in the Swiss licensing exam, we held a symposium with national and international experts to derive corresponding guidelines. Methods: Experts were invited on account of their recognized expertise either in teaching or assessing communication competencies, or in conducting national high-stakes OSCEs. They were asked to propose concrete solutions related to four potential areas for improvement: the station design, the rating tool, the raters' training, and the role of standardized patients. Data gene.rated in the symposium was available for analysis and consisted of video recordings of plenary sessions, of the written summaries of group work, and the cards with participants' personal take-home messages. Data were analyzed using a thematic analysis approach. Results: Nine major suggestions for improving communication-competencies assessments emerged from the analysis and were classified into four categories, namely, the roles of the OSCE scenarios, rating tool, raters' training, and simulated patients. Conclusion: In the absence of established evidence-based guidelines, an experts' symposium facilitated the identification of nine practical suggestions for improving the assessment of communication competencies in the context of high-stakes OSCEs. Further research is needed to test effectiveness of the suggestions and how they contribute to improvements in the quality of high-stakes communication-competencies assessment.