The aim of this prospective study was to evaluate surgical residents' operative skills on the assumption that differences in training might have a significant effect on postoperative complications, their type and incidence. This was accomplished using a departmental microcomputer and special non-commercial personally-developed software. There was no significant clinical difference found in the postoperative complication rate in matched groups of patients treated by senior staff and resident staff of the Department. It is suggested that the close supervision by the senior staff might play a role in this outcome. Although analysis of subgroups of patients sustaining moderate to severe postoperative complications showed a statistically significant difference between these surgeon categories, we may consider this difference attributable to the more complex operative problems handled by the senior staff in the same circumstances.