Balneotherapy of 50 low back pain patients was assessed in this controlled trial. The patients were randomly allocated to 2 groups. The treatment group of 30 patients received balneotherapy and a routine exercise program, whereas the control group of 20 patients followed only the exercise program. Each group was treated for 3 weeks and the patients were evaluated before treatment, after treatment, as well as 1 month after treatment. The groups were comparable in age, sex, duration of pain, intensity of pain, and lumbar flexion. Patients of the balneotherapy group showed statistically significant improvements in visual, analogue pain score, in tenderness assessed by pressure algometer, in knee chest distance, in the modified Schober test, in lumbar extension, in lateral flexion, in finger to floor distance, in straight leg raising test parameters both at the end of the 3-week treatment period as well as 1 month after treatment. Whereas the exercise-only group showed no statistically significant improvement except for pain score. In conclusion, balneotherapy can be suggested as an effective treatment modality in low back pain.