PURPOSE The decrease in resident operative experience due to working-hour directives and sub-specialization within general surgery is the subject of growing debate. This study aims to examine how the numbers of colectomies used for resident training have evolved since the introduction of workinghour directives and to place these results within the context of the number of new general surgeons. METHODS Based on the nationwide database of the Swiss association for quality management in surgery, all segmental colectomies performed at 86 centers were analyzed according to the presence or absence of residents and compared to national numbers of surgical graduates. RESULTS Of 19,485 segmental colectomies between 2006 and 2015, 36% were used for training purposes. Residents performed 4%, junior staff surgeons 31%, senior staff surgeons 55%, and private surgeons 10%. The percentage performed by residents decreased significantly, while the annual number of graduates increased from 36 to 79. Multivariate analysis identified statutory (non-private) health insurance (OR 7.6, CI 4.6-12.5), right colon resection (OR 3.5, CI 2.5-4.7), tertiary referral center (OR 1.9, CI 1.5-2.6), emergency surgery (OR 1.7, CI 1.3-2.3), and earlier date of surgery (OR 1.1, CI 1.0-1.1) as predictors for resident involvement. CONCLUSIONS Only a low and declining percentage of colectomies is used for resident training, despite growing numbers of trainees. These data imply that opportunities to obtain technical proficiency have diminished since the implementation of working-hour directives, indicating the need to better utilize suitable teaching opportunities, to ensure that technical proficiency remains high.