Delayed unions and fibrous or sclerotic non-unions of the carpal scaphoid are frequent sequelae of non-diagnosed or not properly treated fractures. The most important cause of abnormal unions is ischemic necrosis, due to the terminal vascularity of the carpal scaphoid. Conventional X-rays, scintigraphy, and CT do not yield sufficient information for a complete diagnosis; at present, MR imaging represents a valuable alternative, for it is a noninvasive technique able to provide a "biological imaging" of bone. Fourteen patients underwent surgical/nonsurgical treatment, based on the findings supplied by MR imaging. MR reliability was evaluated in relation to the therapeutic results obtained. The study proved MR imaging to provide important information as to therapy planning; in case of surgical treatment, MR imaging helped in choosing the most appropriate location for the insertion of bone graft or screw.