Malignant tumors of the upper extremity are relatively uncommon; however, surgical management presents unique challenges due to the intricate proximity of critical structures, including nerves, major blood vessels, muscles, tendons, and joints, which may either be closely associated or invaded by the tumor. While trying to minimize functional loss, it is imperative not to overlook the oncological integrity of the procedure and the risk of local recurrence. Different reconstructive strategies are available for the structural and functional restoration of upper extremity defects following malignant tumor excisions, ranging from simple techniques to complex. These include primary closure, skin grafting, local and regional flaps, and distant flap transfers, with or without tendon, bone, or nerve grafting depending on the specific requirements of the defect. Each option is carefully considered to maximize the functional outcome and aesthetic restoration of the limb. In this chapter, the malignant tumors of the upper extremity are classified and the reconstructive options following complete surgical resection of the malignancies are described and discussed in detail.