Background: Low Back Pain (LBP) usually describes discomfort and soreness felt in the lower back in particular between costal margins and superior part of buttocks, there may or may not be pain shooting down the leg in conjunction with this nuisance. Purpose:This study was conducted to investigate the effect of non-specific low back pain on knee function in young adults. Materials and Methods: Fifty patients with NSLBP were assigned into Group A and fifty healthy subjects were assigned into Group B ,their age was ranging from 18 and 40 years old, their BMI was between 18.5 to 24.9 kg/m2. Lafayette Hand-Held Dynamometer was used to measure strength of the knee extensors and flexors, Digital Goniometer was used to measure knee range of motion and Knee function was determined by H/Q ratio. Results: The results showed no significant difference between groups in knee flexion and extension strength or ROM.However, both groups exhibited a laterality effect, with one knee being slightly stronger than the other. Conclusion: The study suggested that NSLBP may not significantly impact knee function in young adults.