This prospective consecutive study judges the effectiveness of pulsed low-intensity ultrasound for treatment of boney healing disorders. 86 out of 100 treatments were successful. Although in these 100 cases 64 delayed unions and 36 nonunions were enrolled ultrasound therapy was performed as an alternative to the indicated operation in every case. Excluding ten cases of ununited fractures of the scaphoid no additional therapy was performed in any case. Stratifying the data no significant differences in healing rate and treatment time were observed between delayed unions and non-unions and between atrophic and hypertrophic healing disorders. Judging the healing rate of 86% one has to take into consideration that according to our in- and excluding criteria we had a preselected sample of patients. Nevertheless the effectiveness of pulsed low-intensity ultrasound for treatment of disorders of the fracture repair process is evident.