Background: Stress urinary incontinence (SUI) has an observed prevalence of between 4 and 35%. Aging, obesity, and smoking have consistent causal relationships with the condition.Objective: To elucidate the relationship between obesity and urinary incontinence in women and a possible explanation of this relationship by ultrasound of the urethrovesical angle and bladder neck descent. , and it included 100 obese women compared to 100 normal-weight control women regarding symptoms of SUI, ultrasonographic examination of the bladder neck, and bladder neck descent during straining for the detection of SUI.Results: In the obese group, 70% of patients had symptoms of SUI, whereas in the normal-weight group, 17% of patients had symptoms of SUI, denoting a significant increase among the obese. Ultrasonographic examination revealed that in obese women, the urethrovesical angle is nearly at a right angle with an empty urinary bladder at rest and becomes obtuse at straining; but when the bladder was full, this angle became obtuse at rest and during straining. In normal-weight women, the urethrovesical angle was acute at rest and nearly at a right angle at straining while the bladder was empty, and it became a right angle with a full bladder at rest and slightly obtuse at straining with a full urinary bladder. In obese women, the average bladder neck descent during straining was 10 ± 3.5 mm compared with a mean of 3±1.2 mm in the normal weight group, with a significant difference between the 2 groups. Conclusion:Female obesity is an important risk factor for the occurrence of SUI.