Abstract Background: Low back pain (LBP) and stress urinary incontinence (SUI) are common problems in women, there are many factors that associated with the development of LBP, but there are a limited research that evaluate the relationship between LBP and SUI. Aim of Study: To determine the relationship between stress urinary Incomitance and low back pain in middle-aged women. Material and Methods: One hundred multipara women participated in this study. 50 women complained from stress urinary incontinence (diagnosed by physician) and 50 women were free from stress urinary incontinence (diagnosed by physician). They were selected from Al-Hussein University Hospital in Cairo, Al-Azhar University from November 2020 to March 2021. Their ages were ranged from 35 to 45 years old. Their body mass index was not exceeding 30kg/m2. They were multipara women. Patients with corrected SUI, previous low back surgery, spondylolisthesis and chronic low back pain were excluded from the study. They were divided ran-domly into two equal groups (A&B). Group A consisted of 50 women without SUI. Group B consisted of 50 women with SUI. Pelvic floor muscle strength was assessed by Kegel perineometer and severity of low back pain was assessed by oswestry disability index (ODI) for both groups (A&B). Results: In group (A )There was no statistical significant correlation between oswestry low back pain disability ques-tionnaire (ODI) and pelvic floor muscle strength (PFMS) (r=–0.206; p-value=0.151. While in group (B). There was a statistical significant negative correlation between oswestry low back pain disability questionnaire (ODI) and pelvic floor muscle strength (PFMS) (r=–0.281; p-value=0.048) and in all studied cases (group A + B). There was a statistical signif-icant negative correlation between oswestry low back pain disability questionnaire (ODI) and pelvic floor muscle strength (PFMS) (r=–0.419; p-value=0.001). Conclusion: Accordingly, it can be concluded that there is a positive relationship between low back pain and stress urinary incontinence and presence of stress urinary inconti-nence is predisposing factor for low back pain.