Background: To evaluate the effect of a mentor traineeship in laparoscopic surgery in a teaching hospital. Method: This observational study was performed between January 1997 and December 2004 at Bronovo Hospital, The Hague, The Netherlands. Since January 2001, an advanced endoscopic gynecologist has mentored a trainee in laparoscopic surgery. Data on the trainee’s procedures preceding (1997–2000) and during the mentor traineeship (2001–2004) were compared. The number and type of procedures performed, complications and conversions were derived from a prospectively kept database supplemented by a retrospective chart review. Operating times for total laparoscopic hysterectomy (TLH) were registered to establish the trainee’s learning curve. Results: Since the presence of a mentor, the trainee has performed significantly more advanced laparoscopic procedures. Despite the significant increase in advanced cases, the trainee’s laparoscopic conversion rate to laparotomy remained stable between period 1 and period 2 (7.5 and 4.5%, respectively, p = 0.35, 95% CI –0.033 to 0.092); moreover, for level-3 procedures the conversion rate decreased (p < 0.001, 95% CI 0.30–0.71). Despite the increase in advanced cases, the total complication rate remained stable (3.2–4.5%, p = 0.62, 95% CI –0.07 to 0.04) including the number of level-3 complications (p = 0.63, 95% CI –0.4 to 0.3). A decreasing trend in operating time for TLH was found; however, this was not significant (Spearman correlation coefficient –0.421, p = 0.81). Conclusions: Mentor traineeship in gynecology enhanced the advanced laparoscopic caseload. With the increase in advanced procedures, no increase in conversion rate, complication rate or operating times for TLH was found. Due to the mentorship, patients were not exposed to increased complications and conversions, or to the disadvantages of a prolonged operating time. Predominantly, mentor traineeship facilitated the implementation of laparoscopic surgery into an established gynecological practice in a teaching hospital.