Background Obstructive sleep apnea (OSA) is currently recognized as a risk factor for dysmetabolism. However, the effect of OSA on serum uric acid (SUA) levels in patients with obesity remains unclear. This study aimed to investigate the association between SUA and OSA in patients with obesity and to determine whether bariatric surgery (laparoscopic sleeve gastrectomy (LSG)) could decrease SUA levels. Methods A total of 182 patients with obesity and OSA were recruited for this study. All patients' demographic data, polysomnography (PSG), SUA, blood glucose, lipids, and glycosylated hemoglobinA1c (HbA1c) were recorded. The patients were divided into non-hyperuricemia-OSA (NHUA-OSA, ≤ 360 µmol/L) and hyperuricemia-OSA (> 360 µmol/L) groups according to their SUA levels, and the differences between the two groups were compared and analyzed. Multiple logistic regression analysis was performed to identify the independent risk factors for hyperuricemia in obese subjects with OSA. At follow-up, changes in BMI and SUA levels before and after bariatric surgery were statistically analyzed using repeated measures analysis of variance (ANOVA). Results Hyperuricemia was present in 76.9% of the patients with obesity and OSA. Body mass index (BMI), oxygen desaturation index (ODI), and time spent below 90% oxygen saturation (T90%) were higher, and rapid eye movement (REM) duration during sleep and mean oxygen saturation (meanSpO2) were lower in the HUA-OSA group than in the NHUA-OSA group (all P < 0.05). Multiple logistic regression analysis showed that BMI was an independent risk factor for hyperuricemia in patients with obesity and OSA (OR 1.103, 95% CI1.032–1.178, P = 0.004) after adjusting for confounding factors. Receiver operating characteristic (ROC) curve analysis revealed that the area under the curve (AUC) for BMI was 0.695 and the optimal cutoff value was 41.80kg/m2. The BMI and prevalence of hyperuricemia gradually decreased in 23 patients reassessed at the 1, 3, and 6 months follow-ups after bariatric surgery (all P < 0.05), while the SUA level increased at 1 month and started to decrease only at 3 months after the surgery (P < 0.05). Conclusion BMI is a useful screening tool for detecting hyperuricemia in patients with obesity and OSA. Our results also demonstrated that bariatric surgery can effectively decrease SUA levels.