Metabolic dysfunction-associated steatotic liver disease (MASLD) is the most common liver disease worldwide and simultaneously the most common indication for liver transplants in Western countries This study aims to evaluate the effectiveness of laparoscopic sleeve gastrectomy (LSG) or Roux-en-Y gastric bypass (RYGB) on MDASLD histologically and biochemically. 14 studies met our criteria with a total population of 1942 who underwent LSG or RYGB 1–14. The Newcastle-Ottawa Scale (NOS) was used for quality evaluation of the included studies. Results: Both surgeries were effective in decreasing laboratory biomarkers like ALP, GGT, AST, and ALT with non-significant superiority of LSG over RYGB which did not significantly improve the AST level after one year. LSG showed more decrease in ALT levels (MD = −17.56, 95% CI = (−23.04, −12.089), p 0.001) and LSG was associated with increased change in NAS score with slight superiority. Both LSG and RYBG improve NAD and NASH outcomes after one and 10 years of surgery. However, randomized clinical trials with large samples are needed to confirm these results.