The opioid crisis caused a huge health concern in the United States. Despite this, few studies have examined the influence of opioid-related disorders (OD) on outcomes after bariatric surgery. The major goal of this study is to determine the impact of OD on in-hospital outcomes for patients undergoing bariatric surgery.The National Inpatient Sample (NIS) database from 2016 to 2020 was used to evaluate patients with OD who underwent bariatric operations including sleeve gastrectomy, Roux-en-Y gastric bypass, and biliopancreatic diversion with duodenal switch. The non-OD comparison group was created using a propensity score match (1:1). Weighted analysis was carried out utilizing NIS-provided weights. The odds ratios were obtained using multivariate logistic regression.A total of 159,455 patients who underwent bariatric surgery were evaluated. Propensity score matching and weighted analysis were used to compare 11,025 in the OD group and 11,025 in the non-OD group. OD was an independent predictor for postoperative complications (odds ratio: 1.29, 95% confidence interval: 1.19-1.39, p < 0.001). Among complications, OD was a predictor for bleeding complications, postoperative nausea and vomiting, anastomotic leak, and mechanical ventilation. In addition, the OD group experienced significantly longer lengths of stay (LOS) and a higher total hospital charges.In patients undergoing bariatric surgery, OD is associated with a significantly higher risk of postoperative complications, as well as increased LOS and total hospital charges. These patients may benefit from further preoperative optimization, including decreasing the opioid dose and closer postoperative monitoring.