A 15-year-old competitive right-handed high school baseball pitcher experienced an acute onset of right elbow pain when throwing. He initially treated it conservatively with rest alone for 3 months, but on return to throwing, he was still experiencing pain. Radiographs revealed that he had a persistent olecranon physis. He proceeded with a trial of low-intensity pulsed ultrasound therapy and attained radiographic evidence of bony union at 7 months postinjury, thus avoiding surgical intervention. He returned to pitching competitively 9 months after injury without elbow pain. This is the first reported case of using ultrasound bone stimulation for treatment of a symptomatic persistent olecranon physis in a baseball pitcher.