Background: Urinary stress incontinence (USI) is defined as involuntary leakage of urine. Two times as many women as men experience incontinence. To assess urinary incontinence and its subtypes, many investigations are used. The primary diagnostic imaging modality used for examining the lower urinary tract in cases diagnosed with urine leakage is transperineal ultrasonography. It has been demonstrated that it helps to increase the precision of morphological and functional abnormality when combined with the history, clinical examination, and urodynamics. Patients and methods: This case control study included two groups; 17 female complaining of  USI and 17 healthy  females  examined by trans-perineal ultrasonography. The difference of both α and β angles at rest and at stress as well as other urethral parameters. Results: The alpha and beta angles at stress and the difference between rest and stress (R alpha and R beta) were significantly higher in cases than controls. No detectable significant difference between both groups regarding alpha angle at rest & beta angle at rest. No appreciable significant difference between the study groups as regards the bladder wall, urethral length, width, Pubo-urethral distance at rest and at stress. Conclusion: Transperineal ultrasonography can assess stress incontinence by measuring different angles and other parameters. There were no difference between cases and controls during rest for both alpha and beta angles while a significant value showed up during stress. The other parameters showed no significant value between two groups.