Two infants of 24 and 20 months of age with painful local swelling at the femoral and clavicular regions were investigated by ultrasound after a negative radiographic study of the adjacent bones. In both children high resolution ultrasound clearly revealed the presence of bone fractures in addition to the soft tissue hematomas. These fractures were confirmed by a repeat radiographs performed 6 and 8 days later. Although sonography is not the method of choice for the detection of bone fractures, it may be worthwhile to examine the bone contour for a fracture when a painful swelling adjacent to bone is present. The method may be particularly rewarding in children due to its rapid non-invasive nature and to the small tissue thickness that has to be penetrated.