BACKGROUND: Experience in terms of surgical case numbers required to develop proficiency for oncologic adequacy after sphincter-saving laparoscopic rectal cancer surgery has not been established. METHOD: Three hundred seventeen consecutive patients underwent sphincter-saving laparoscopic rectal cancer surgery with curative intent performed by single surgeon. The learning curve was estimated using risk-adjusted cumulative sum (RA-CUSUM) and the graph of 195 consecutive patients who were treated by another surgeon was used to evaluate inter-surgeon variability in the learning curve. RESULTS: Overall, the 3-year local recurrence rate was 7.7% (95% confidence interval [CI], 6.4%-9.0%). The RA-CUSUM analysis demonstrated a learning curve of 110 cases for local recurrence for both of surgeons and 50-70 cases for CRM involvement. The 3-year local recurrence-free rate was better during the experienced period than during the learning period (95.1% [95% CI, 91.6%-97.1%] vs. 89.5% [95% CI, 84.4%-93.0%]; P = 0.029). These differences were obvious in subgroup analysis of stage III tumors (93.4% [95% CI, 86.6%-96.8%] vs. 78.6% [95% CI, 68.5%-85.3%]; P = 0.013). CONCLUSIONS: Local recurrence rates decreased with increasing surgeon experience, as did other short-term outcomes, especially in advanced disease cases.