---

Urinary incontinence is defined as involuntary loss of urine, which is a social and hygienic problem. The study is about quantity of stress incontinence in high school 15-17 years old girl during (1999-2000). This is a descriptive cross-section study. From 711 cases, 454 (76.4%) did not have urine stress incontinence (USI) and 166 (23.6%) had this problem. From these 166 members 24.1% were 15 years old, 35.8% were 16 years old and 40.1% were 17 years old. Therefore with increasing age we have more urine stress incontinence and the most prevalence of USI occur during laughing predisposing factor for USI is urinary tract infection (UTI) and trauma to hip. 27% of these girl’s mothers had USI and the population was chosen by cluster sampling. Therefore genetic factor could be a cause. The most presentation of USI is in the estrogenic phase and we didn’t have any USI report in the progestronic phase. According to our results the incidence of USI among 15-17 year girls students was 23.6%.