To determine the validity of the Bonney test as a prognostic screening test for urinary incontinence, the urethral and urethrovesical functions were studied under resting and stressful conditions. The characteristic similarity of changes was evident in the functional profile length, closure pressure, and cough pressure profile of the urethra during performance of the Bonney test and intentional urethral occlusion. This study clearly invalidated the Bonney test by objectively demonstrating that the Bonney test restored continence under stress of coughing by obstructing the urethra and urethrovesical junction.