Background High body mass index (BMI) is thought to be a preoperative risk factor for surgical treatment. Until now, few studies have investigated the long-term impact of preoperative high BMI on advanced gastric cancer (GC) patients who underwent laparoscopic gastrectomy (LG). Therefore, the present study was designed to compare clinical outcomes between high BMI and normal BMI patients who underwent LG. MethodsWe retrospectively investigated 282 pathological stage II~III GC cases who underwent radical LG plus D2 lymphadenectomy from February 2009 to May 2018. Based on the China BMI classification, the patients were classified into a high (BMI ≥ 24 kg/m2) or normal (BMI < 24 kg/m2) BMI group. The clinical characteristics, intraoperative findings, short-term and long-term outcomes of the two groups of patients were then compared. Results The high BMI group had longer operation time (160.1 ± 36.0 minutes vs. 147.7 ± 33.7 minutes; P = 0.005) and greater intraoperative bleeding (138.3 ± 239.4ml vs. 86.6 ± 67.7ml; P = 0.002) compared to the normal BMI group. Moreover, shorter time to flatus, starting the soft diet, removing drain tube and length of stay (all P < 0.05) were observed in the high BMI patients. However, there was no significant difference in relapse-free survival or overall survival between the two groups. Conclusion Patients with high BMI was associated with longer operation time and greater amount of intraoperative bleeding but had faster recovery as compared to those with normal BMI. Also, LG can be considered as safe with no significant difference in terms of short- and long-term outcomes on the peri- and post-operative outcomes between the two BMI groups of patients. Nevertheless, these surgeries for high BMI patients should be performed by experienced surgeons.