Background There may be concems over disbenefits to patients who have chosen to undergo laparoscopic gastrectomy by experts in open gastrectomy,considering the disparity between the level of proficiency in open gastrectomy,at which they are already experts,and that in laparoscopic gastrectomy,at which they are beginners.The aim of this study was to compare surgical radicality and outcomes between laparoscopic gastrectomy and open gastrectomy during the leing period of laparoscopic gastrectomy for a senior surgeon who was already an expert in open gastrectomy.Methods Data of short-term surgical outcomes were obtained from patients following laparoscopy assisted distal gastrectomy (LADG) by a surgeon.The initial and following 30 experiences were grouped into LADG-Ⅰ and LADG-Ⅱ,respectively.Patients who underwent open distal subtotal gastrectomy (ODSG) and yet could have been candidates for LADG were grouped into ODSG.Known indicators of proficiency levels and the postoperative hospital course were compared.The consequences of extended lymphadenectomy,and the radicality of surgery by completing D2 lymphadenectomy were analyzed.Results The LADG group revealed longer operation time and less bleeding compared to the ODSG group (P ＜0.001).The number of retrieved lymph nodes and the rate of complications were not significantly different.In the LADG-Ⅰ group,the D1+:D2 ratio was 4:1,showing significant differences from those in the LADG-Ⅱ (0.36:1) and ODSG (0.16:1) groups (P ＜0.001).The surgeon was able to complete D2 lymphadenectomy during LADG without significant change in the amount of bleeding and the rate of complications,but with a longer operation time (P=-0.009).The number of lymph nodes from the 12a station was not significantly different between the LADG and ODSG groups with D2 lymphadenectomy.Conclusions The surgical outcomes were comparable between LADG and ODSG even during the leing period of LADG,and the equivalence of radicality in lymphadenectomy was soon achieved.As long as the surgeon can accept a long operation time,an expert in open gastrectomy should not refrain from performing laparoscopic gastrectomy in well selected patients because of concs about disbenefits to patients from choosing laparoscopic gastrectomy over open gastrectomy.