The purpose of this study was to investigate the effects of pulsed short-wave diathermy (PSWD) in patients with low back pain (LBP). Sixty patients with a diagnosis of disc degeneration and root irritation participated in this study. Patients were divided into 3 groups (20 patients in each group), and each group underwent a different physiotherapy program. Continuous short-wave diathermy (CSWD) and exercise were given to the first group, 200 Hz PSWD and exercise were applied to the second group while 46 Hz PSWD and exercise were given to the third group. All subjects were evaluated for their pain perception level, muscle strength and lumbar range of motion (ROM). Results showed significant improvements in measured parameters in each group after the treatment. However, pain relief, increase in muscular strength and ROM were significantly higher in PSWD groups than in those who were treated by continuous diathermy. We concluded that all the interventions used in this study were effective in reducing low back pain but PSWD was found to be more effective than CSWD.