The aim of this study was to investigate and compare the efficacy of aerobic exercises versus strengthening, stretching and mobilization exercises in patients with subacute or chronic low back pain. Forty patients were recruited for the study and randomly allocated to two groups. All patients were evaluated at admission, mid-treatment and termination of the program by visual analog scale (VAS), face scale, weekly analgesic intake and Million visual analog scale for pain. They were also scored by Roland-Morris scale and Oswestry scale for functional impairment. Beck depression inventory was used to evaluate depression and lumbar range of motion was measured by inclinometry, Schober, finger tip to floor distance. The aerobic exercise group was also evaluated for VO2max and anaerobic threshold levels. Both groups showed significant improvement in all parameters at termination. Comparison between groups showed a higher significant improvement in depression and functional improvement parameters in the group given strengthening, stretching and mobilization exercises by physiatrist.