Metabolic syndrome (MetS) is strongly linked to insulin resistance and has a high resolution rate after bariatric surgery. This study aims to determine whether post over preoperative ratios of surrogate insulin resistance markers (HOMA, TyG, and TG/HDL-c) are associated to postsurgical MetS reversal. This is a retrospective cohort study which involved 96 subjects with MetS who underwent Roux-en-Y gastric bypass (RYGB). Post over preoperative ratios of TyG and TG/HDL-c indexes were statistically associated to MetS resolution. The use of these ratios as a way to assess postsurgical insulin sensitivity response appears to be a simple and useful tool in clinical practice.