Background <p>Collaborative assessment formats have gained increasing attention in medical education due to their potential to foster clinical reasoning, teamwork, and to reduce examination-related stress. However, evidence for their feasibility and acceptance within summative undergraduate medical curricula remains limited.</p> Objective <p>This study aimed to evaluate the feasibility and student perceptions of a case-based, collaborative summative examination (“whisper exam”) in undergraduate medical education. Specifically, we explored students’ perceptions of stress, preparation effort, teamwork, and the alignment between self-assessement and actual examination performance.</p> Methods <p>A single-center, descriptive feasibility study was conducted with third-year medical students (<i>n</i> = 350) following a laboratory course in hygiene, microbiology, and virology. Students completed a digital, case-based examination using key-feature questions in pairs. Examination performance was recorded at the team level. Student perceptions were collected via a post-exam voluntary questionnaire and analyzed descriptively.</p> Results <p>The overall pass rate was 93.1% (326/350 students). Survey responses were obtained from 190 students (54.3%). Most respondents reported lower perceived stress compared to individual examinations and described teamwork as constructive and enjoyable. Preparation effort was reported to be comparable to that required for individual examinations. Self-assessment of performance broadly aligned with examination outcomes, although a tendency toward underestimation was observed.</p> Conclusion <p>The whisper exam was feasible to implement within a summative undergraduate curriculum and positively perceived by the majority of participating students. Findings suggest that collaborative, case-based examinations may complement existing assessment formats. Further research using comparative and multi-institutional designs is required to evaluate educational impact and validity.</p>