Vascularized bone transfer is increasingly recognized as a very useful and versatile technique for reconstructing massive bone defects in the upper limb or in patients with especially challenging conditions, such as infected nonunions and nonunions associated with radionecrosis of bone. It is especially indicated for the humerus and shoulder region with more selected applications in the forearm or wrist. Although technically challenging, the outcomes of this procedure justify consideration along with alternative methods for major reconstructions of the upper limb.