Morbid obesity (body mass index (BMI) ≥40 kg/m² or ≥35 kg/m² with comorbidities) predisposes patients to multiple urological disorders, including urinary incontinence, overactive bladder, erectile dysfunction, hypogonadism, nephrolithiasis, obesity-related kidney disease, renal cell carcinoma, and aggressive prostate cancer. Bariatric surgery is the most effective durable treatment for severe obesity. Glucagon-like peptide-1 receptor agonists, including semaglutide and tirzepatide, have revolutionised obesity pharmacotherapy. This systematic review evaluates the urological complications of morbid obesity and the effects of bariatric surgery and glucagon-like peptide-1 receptor agonists on these outcomes. We searched MEDLINE, Embase, Scopus, and the Cochrane Library (January 2000 to June 2025) for studies reporting urological outcomes in adults with BMI ≥35 kg/m². Two reviewers independently screened and extracted data. We assessed risk of bias using the A Measurement Tool to Assess Systematic Reviews (AMSTAR) version 2 and the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE). Eighty-four studies (>165,000 participants) met the inclusion criteria. Obesity increases renal cell carcinoma risk (relative risk: 1.5-2.0) and prostate cancer mortality (hazard ratio: 1.19-1.24) but paradoxically reduces prostate cancer incidence. Urinary incontinence and overactive bladder improve or resolve in 50-70% of women after bariatric surgery. Erectile dysfunction and hypogonadism improve after bariatric surgery, with International Index of Erectile Function (IIEF) scores increasing 4-6 points and testosterone rising 30-50%. Glucagon-like peptide-1 receptor agonists increase testosterone (standardised mean difference: 1.39 ng/mL) and improve erectile function. Tirzepatide reduces urinary albumin-to-creatinine ratio by 19-47% and preserves estimated glomerular filtration rate. Roux-en-Y gastric bypass increases nephrolithiasis risk 2.5-4-fold via enteric hyperoxaluria, whereas sleeve gastrectomy does not. Robot-assisted surgery in obese patients achieves complication rates comparable to those of non-obese patients after comorbidity adjustment. Bariatric surgery improves obesity-related urological morbidity, but Roux-en-Y gastric bypass increases stone risk. Glucagon-like peptide-1 receptor agonists offer a promising alternative with evidence for testosterone restoration, improved erectile function, and renal protection. Preoperative urological assessment, procedure selection, and multidisciplinary care are essential.
