Background <p>Most studies demonstrated that the learning curve of total extraperitoneal hernioplasty (TEP) is around 30–80 cases. All these studies were performed by a single surgeon who had little or no experience of TEP repair before. However, with mentoring by experienced surgeon, the second-generation surgeon may get more familiar with the anatomy and procedures of TEP than the pioneer surgeon. Besides, the surgical caveats would be further understood and pitfalls avoided by mentoring with the pioneer surgeon. The aims of this study were to investigate the effects of mentoring by pioneer surgeon to the second-generation surgeon in the TEP operation by comparing the learning curve and complications of pioneer and second-generation surgeon.</p> Methods <p>We retrospectively reviewed our TEP cases performed by the two surgeons, the pioneer surgeon and the second-generation surgeon, in general surgery department in Chang Gung Memorial Hospital, Keelung division. The reviewed period was between January 2016 and December 2021. The pioneer surgeon performed the TEP surgery by himself. The second-generation surgeon attended 20–30 cases of TEP done by pioneer surgeon. Then, the pioneer surgeon mentored the second-generation surgeon’s first 10 TEP cases. By comparing the operation time, the intraoperative and post-operative complications, cumulative sum (CUSUM) learning curve was used for analysis.</p> Results <p>The CUSUM analysis reveals that the learning curve of TEP is around 45 procedures in the pioneer surgeon and 30 procedures in the second-generation surgeon. The median operation time in pioneer surgeon and second-generation surgeon is 103.5 vs 90 min (<i>p</i> = 0.03). The overall intraoperative and post-operative complications between pioneer and second-generation surgeon reveal no significant difference. After crossing the learning curve, the operation time of pioneer surgeon and the second-generation surgeon decreased significantly, from 114 to 93 min (<i>p</i> = 0.008) and from 103 to 87.2min (<i>p</i> = 0.032), respectively. However, there was no significant difference in the overall post-operative complications.</p> Conclusions <p>By mentoring with the pioneer surgeon, the second-generation surgeon may achieve the learning curve quicker than the pioneer surgeon in terms of operation time. After reaching the learning curve, the operation time before and after learning curve reveal significant different in both surgeons while the overall post-operative complications reveal no significant different.</p> Graphical abstract <p></p>