The aim of the present study was to evaluate the effect of laparoscopic sleeve gastrectomy (LSG) on nonalcoholic steatohepatitis (NASH).Seventy-four patients with severe obesity underwent LSG and concomitant intra-operative liver biopsies from 2008 to 2017. Fifty-one patients fulfilled criteria for NASH and 22 patients underwent repeat percutaneous liver biopsy at 1 year after LSG. Mean excess body weight loss at time of repeat biopsy was 57.0%. Mean NAFLD activity score was decreased from 4.7 to 0.2. At the second biopsy, steatosis resolved in 62%, lobular inflammation resolved in 39%, ballooning resolved in 69%, and fibrosis resolved in 39%. Significant differences were observed in the following variables pre- and post-LSG: HOMA-IR (6.3 vs 1.7), liver volume (2,265 vs 1,598 mL), and visceral adipose tissue (271 vs 148 cm2). Metabolic surgery-induced weight loss should be considered as a treatment of choice for NASH patients with severe obesity.