 Subjects n48 with clinically diagnosed acute bacterial rhinosinusitis ABRSwill included. The antibiotic group will receive amoxicillin 500 mg 3 times per day for 10 days. The ultrasound group will receive therapeutic ultrasound over sinuses at 1.0 Wcm2 in continuous mode for 10 minutes once a day for 4 consecutive days. Improvement of symptoms pain and congestion; numeric rating scale; 0-10 from day 1 to days 4 and 21 will be recorded. Relapses, side-effects and satisfaction with treatment will be assessed at one-year follow-up. 