A prospective experimental study on 97 patients of chronic low back pain was conducted to find out the effects of shortwave diathermy. They were divided randomly into two groups and treated with non steroidal anti inflammatory drugs, exercises, activities of daily living instructions and with or without shortwave diathermy. After six weeks of treatment, improvements were observed in both the groups. But significant difference in improvement was found in shortwave diathermy group than in placebo group. The present study suggests that shortwave diathermy is effective for the treatment of patients with chronic low back pain.