Several years ago, low-intensity pulsed ultrasound (frequency 1.5 MHz; signal burst width 200 micros; signal repetition frequency 1 KHz; intensity 30 mW/cm2) was shown to accelerate fresh fracture healing both clinically and experimentally. On the basis of a prescription use registry, this paper reports on the use of low-intensity pulsed ultrasound in the therapy of 951 delayed unions and 366 nonunions. The overall success rate for delayed unions was 91% (average healing time 129+/-2.7 days) and for nonunions 86% (average healing time 152+/-5.3 days). Stratifying the data, it becomes clear that patient medication with calcium channel blockers, non-steroidal anti-inflammatory drugs, and steroids is a negative predictor for healing nonunions, as well as renal or vascular insufficiency. Patients who were smokers during ultrasound therapy had lower healing rates than those who never smoked. When comparing the patients of our own clinic treated with low-intensity ultrasound under study conditions which demonstrate that if healing was achieved it was an effect of the ultrasound therapy to the worldwide prescription use registry, no difference was seen in healing rate, healing time, or fracture age. Therefore, the results of these two populations support each other. Low-intensity pulsed ultrasound may provide a method of nonoperative treatment of great promise for healing disorders. Determination of ranking of this new method should be done within the near future.