Objective: This study aimed to determine the efficacy of ultrasound therapy in patients with primary nocturnal enuresis. Material and methods: Thirty-five patients with enuresis were included the study. Patients were divided into two groups: 27 patients with enuresis were treated with ultrasound with irradiation and heating, and eight patients with enuresis were treated with ultrasound without irradiation or heating (placebo group). Ultrasound therapy was performed using the Therasonic 350 machine. The ultrasound therapy was applied to the skin of lumbosacral region. A treatment course of ultrasound comprised 10 sessions of 0.8 W/cm(2) intensity applied daily for 8 min. Symptoms were evaluated 1 week, and 3, 6 and 12 months after the treatment. Results: Twenty-two (81.5%) patients responded to the ultrasound therapy at the first week after the treatment. The effect of ultrasound started immediately after the treatment and continued during the 12 months of the follow-up period. Conclusion: Ultrasound therapy seems to be effective in the treatment of primary nocturnal enuresis in the 1 year follow-up period.