Outpatient diagnosis of acute bacterial sinusitis, using only traditional physical examination and clinical criteria, results in the overuse of antibiotics in patients with upper respiratory complaints. Point-of-care maxillary sinus ultrasound is easy to learn and quick to perform in a primary care clinic. The technique can reduce antibiotic prescribing by reassuring both patients and providers of the absence of fluid in the sinus, the hallmark of maxillary sinusitis. A review of the literature, description of technique, and results of sinus ultrasound implementation in a large internal medicine clinic are included.