Background: Surgical residents rotate on different surgical services in order to obtain a comprehensive surgical experience, typically spending anywhere from 1-4 months. Dedicated non-physician surgical assistants (NPSA), by virtue of repetition and familiarity with the procedure, also assist primary surgeons in bariatric surgery. We wanted to test the hypothesis that operative time would be longer for resident-assisted (RA) Laparoscopic Roux-en-Y Gastric Bypass (RYGB) versus non-physician surgical assistant (NPSA) assisted cases. Our goal is to initiate more consistent and effective resident teaching methods (such as simulation-based and video-based techniques) in conjunction with intra-operative training, shorten the learning curve for advanced laparoscopic procedures and decrease operating room time, and consequently improve patient outcomes.Methods: We conducted a retrospective analysis of 1031 bariatric cases from 2001-2008 by a single surgeon at our institution of which 680 were uncomplicated laparoscopic retro-colic gastric bypass procedures. Patients who underwent secondary procedures (cholecystectomy, liver biopsy, endoscopy, etc.) were excluded. Complete data was available for 300 patients. 49 cases were performed with senior surgical residents while 251 cases were performed with a single, dedicated non-physician surgical assistant (NPSA). Results: We found a statistically significant difference between Resident-Assisted cases vs. NPSA’s (3.7 hrs +/- 0.8 [2.5-6.4] versus 2.5 hrs +/- 0.5hrs [1.4-4.5]; p<0.0001). As expected, there was a difference in operative time between males vs. females patients (2.9 hrs versus 2.6 hrs p<0.01). The interaction between assistant and patient gender was not significant (p=0.70). Analysis of the OR times of the NPSA showed a learning curve of ~50 cases with a plateau at 2.4 hours.Conclusion: In assisting advanced laparoscopic cases such as the gastric bypass, resident-assisted operative time was significantly longer than with a single NPSA. The learning curve in performing bariatric surgery is significant not only for the surgeon but for the assistant as well. This supports the need for a more effective, consistent method for resident as well as NPSA training in advanced laparoscopy to shorten the learning curve, decrease operative time and improve patient outcomes.