Objective: To obtain detailed information about the degree of surgical trainee supervision and delegation of procedures in a subspecialised department. Design: Operative procedures and their logical components were recorded in a database constructed in Microsoft Access. Information about operating surgeon and assistants and their grade was registered prospectively over 12 months. Subjects and methods: A total of 1250 intermediate or major procedures were performed by eight consultants, one staff specialist, four senior registrars, three specialist registrars, and five registrars. Main measure: Number of components performed by surgeons in each grade and the degree of supervision and delegation. Results: Eight hundred and eighty five of the operations were elective, while 365 were done as emergency procedures. Emergency procedures were far more often done by surgeons in training than by a staff surgeon, while the opposite was true for elective operations. Out of 323 elective operations done by surgeons in training, 189 were done under supervision (58.5%), while 119 out of 276 emergency operations done by surgeons in training were supervised (43.1%; p=0.0002). One hundred and twenty eight of 638 (20%) open abdominal operations were done by the most junior surgeons, and yet they closed 36% of all abdominal wounds. Although the most junior surgeons only served as operating surgeons in 39 of 334 bowel operations (12%), they constructed 24% of all stomas, and 20% of all anastomoses. Registrars and specialist registrars never constructed stomas or anastomoses without supervision. Conclusion: Detailed information about individual and general training and supervision was achieved by a simple registration. Significant additional information was obtained about the extent of delegation of components compared with standard registration of operative procedures.