Introduction: The clinical examination and other practical clinical skills are fundamental to guide diagnosis and therapy. The teaching of such practical skills has gained significance through legislative changes and adjustments of the curricula of medical schools in Germany. We sought to find out how well final year undergraduate medical students master practical clinical skills. Methods: We conducted a formative 4-station objective structured clinical examination (OSCE) focused on practical clinical skills during the final year of undergraduate medical education. Participation was voluntary. Besides the examination of heart, lungs, abdomen, vascular system, lymphatic system as well as the neurological, endocrinological or orthopaedic examination we assessed other basic clinical skills (e.g. interpretation of an ECG, reading a chest X-ray). Participants filled-out a questionnaire prior to the exam, inter alia to give an estimate of their performance. Results: 214 final year students participated in our study and achieved a mean score of 72.8% of the total score obtainable. 9.3% of participants (n= 20) scored insufficiently (<60%). We found no influence of sex, prior training in healthcare or place of study on performance. Only one third of the students correctly estimated their performance (35.3%), whereas 30.0% and 18.8% over-estimated their performance by 10% and 20% respectively. Discussion: Final year undergraduate medical students demonstrate considerable deficits performing practical clinical skills in the context of a formative assessment. Half of the students over-estimate their own performance. We recommend an institutionalised and frequent assessment of practical clinical skills during undergraduate medical education, especially in the final year.