PURPOSE: There has been much concern regarding the impact of work-hour reforms on the operative case volume of surgical residents. Operative case volume by PGY year and clinical rotation were examined to determine if changes in work hours affected residents' operative case volume. METHODS: A careful but aggressive plan of work-hour reduction was devised for the residency of the authors' institution with the goal to decrease work hours while maintaining optimal patient care and resident education, including operative case volume. Changes made included hiring physician extenders (PEs), decreasing call schedules to every fourth night (with the next day free from clinical activities-Q4) or call from home (HC), and night float rotation coverage for services (NF). Case volume before (academic year 2002) and after (academic year 2003) changes were compared by PGY year, for all residents and for specific rotations-private general surgery, which had changes of PE, HC, and NF for PGY5; PE, Q4 and NF for PGY1 and 10% exemption for work hours; Churchill service (a resident-run ward teaching service), which had changes of PE and Q4 for PGY5 and PGY1 and 10% exemption for work hours; and vascular surgery, which had HC and NF for PGY5. Total case volume on these services was likewise compared. Statistical analysis was by student t test. Operative case volume was measured with data from the resident-entered information on the ACGME Surgical Operative Log (SOL). Case volume for PGY4 residents could not be compared over this time period because of lack of access to archived data by PGY year for graduated residents through the ACGME SOL. Work hours before and after rotation changes were measured with an intranet-based monitoring system. This article is a retrospective review of the affects of these work-hour changes on operative case volume. RESULTS: Total case volume for the general surgical services (both private and Churchill) was unchanged over this period (5905 in 02, 5930 in 03), and likewise for the vascular service (1101 vs 1196). Overall, there was no change in mean operative volume per year for surgical residents in this program (231 cases in 2002, 246 cases in 2003; p = 0.61). For PGY5 residents, the case volume increased; 339 cases 02, 390 in 03, and p = 0.05. Mean case volume for PGY5 residents increased on the private general surgery service (136 in 02, 160 in 03, p = 0.03), but it remained stable on the Churchill service (137 in 02, 158 in 03, p = 0.39) and vascular service (65 in 02, 73 in 03, p = 0.42). For PGY3 residents, case volume remained stable (171 in 02, 187 in 03, p = 0.62), as it did for PGY2 and PGY1 residents (PGY2: 148 in 02, 121 in 03, p = 0.12; PGY1: 265 in 02, 246 in 03, p = 0.23). However, operative case volume for PGY1 residents did decrease on the private general surgery service (mean 52 cases per month 02, 43 cases per month 03, p = 0.07), while remaining stable on the Churchill service (mean 23 cases per month 02, 25 cases per month 03, p = 0.66). Average hours worked per week decreased significantly over the time period. Before work-hour reforms, residents' average work hours were as follows: PGY1 105, PGY2 97, PGY3 78.7, PGY4 111, and PGY5 92. After the changes, average work hours were PGY1 81.5, PGY2 77.7, PGY3 78.7, PGY4 75.5, and PGY5 75.9. CONCLUSIONS: Work-hour limitation can be devised to maximize resident education, optimize patient care, and maintain resident operative volume. Although some changes (HC, PE, NF) seemed to increase the operative case volume for PGY5 residents, others had no effect (Q4, HC). There does not seem to be a clear relationship between types of changes and case volume. At the PGY1 level, Q4 and PE changes decreased operative experience on 1 rotation but not on another, although the difference in this decrease seems clinically insignificant. Individualization of changes to meet the needs of specific rotations seems more important than specific changes in coverage pattern. Perhaps the most important finding is that changes can be made to bring work hours into compliance without materially effecting operative case volume.