Sixty patients (>45 years) with knee osteoarthritis were randomized to receive rectus femoris stretching exercises in addition to a 4-week lower body stretching and strengthening exercise program (n=30) or the 4-week program alone (n=30). The outcomes of interest included pain on a Visual Analog Scale (VAS), Western Ontario and McMaster Universities (WOMAC) osteoarthritis index, range of motion, and gait parameters (step length, speed). Outcomes were assessed before and after treatment. The results demonstrated significantly better WOMAC scores, better flexion range of motion and pain scores on both sides, and superior gait parameters in the rectus femoris stretching group. Stretching the rectus femoris may provide clinical benefits for patients with knee osteoarthritis.