The purpose of this study was to determine the effect of sciatic nerve mobilization technique on perceived pain, straight leg raise test (SLR), and strength of knee extensor, location of symptoms (LOS) in patients with chronic low back pain. 22 patients with chronic low back pain were recruited for this study. The subjects were randomly assigned to either the experimental group (EG) or the control group (CG), with 11 patients in each group. All patients received a routine physical therapy (hot pack and transcutaneous electrical nerve stimulation). The mobilization technique of the sciatic nerve was performed for 10 min in the case of the EG subjects. Outcome measurements included the level of the perceived pain, SLR, and strength of the knee extensor, LOS. The measurements were recorded 3 times: before the intervention, after the intervention, and at 1 hour of follow up. The two groups did not significantly differ with regard to the level of perceived pain, SLR, and strength of the knee extensor, LOS before the test (p>.05). In the case of the EG subjects, all the variables measured after the intervention significantly differed from those measured before the intervention (p<.05). However, in the case of the CG subjects, a significant difference was noted only with regard to the level of perceived pain (p<.05). The findings indicate that sciatic nerve mobilization technique exerts a positive effect on the control of subjective symptoms and knee strength in patients with chronic low back pain. Further studies are required to generalize the result of this study.