PURPOSE In response to the Accreditation Council for Graduate Medical Education (ACGME) mandated 80-hour workweek, the night float coverage model was one system created to comply with the work-hour restriction. However, concern has risen as to the operative case volume achieved with this model. The purpose of this study is to determine which system of call (night float vs traditional rotating call) provided the senior surgical resident with the greatest surgical case volume while in compliance with the 80-hour workweek. METHODS A nonrandomized sequential study to evaluate the ACGME surgical operative logs (SOLs) for surgical chief residents at Memorial University Medical Center (MUMC), which is a level 1 trauma center, from 2006 to 2008 was conducted. The night float system (NFS) consisted of a PGY-4 or -5 assigned to in-house general surgery and trauma call from 6:00 pm to 6:00 am Monday through Friday morning and a 24-hour shift from 6:00 am on Sunday to 6:00 am Monday morning. Two months of night call rotations (nights) are performed each year per resident with the other 10 months devoted to daytime rotations (days). Conversely, the traditional rotating call schedule (TCS) placed each resident on-call every sixth night for a 30-hour period. The TCS required the resident to average approximately 3 weekday and 2 weekend calls per month. The data examined include all cases on the ACGME SOL submitted by each PGY-4 and 5 residents over a 2-year span. Specific designation of cases between night and day rotations was evaluated while on the NFS, and the total cases volume performed on the NFS and the TCS were analyzed. RESULTS An evaluation of the 2006-2007 (NFS) year demonstrates an average of 16 cases per month while on nights as compared with 20 cases per month while on day rotations. The caseload on the night rotation was less than day rotations at the PGY-4/5 level. An analysis of the 2006-2007 (NFS) and 2007-2008 (TCS) for PGY-4/5 residents revealed an average total caseload of 224 and 276, respectively. A statistically significant total case difference of 52 cases over the entire year between the 2 systems of call was appreciated. CONCLUSIONS Because of the work-hour restrictions, maximizing surgical education has become a necessity. With the various call systems used throughout general surgery programs, this study specifically compares a traditional 1-in-6 call schedule versus an NFS. Senior residents lost significant operative experience while operating under an NFS as compared with a TCS. Evidence suggests that the more hours spent by a chief resident during normal operative time elicits more operative experience.