This case series evaluates 12 patients presenting posttraumatic infected nonunions affecting long bones of the upper extremity, treated with staged reconstruction using polymethylmethacrylate spacers with antibiotics in the first stage and bone graft impregnated with antibiotics in the definitive surgical procedure. Five nonunions affected the humerus, four the ulna and three the radius. All nonunions were atrophic. Patient's age averaged 35.9 years. The size of the bony defect averaged 2.8 cm. Time between original trauma and revision surgery averaged 9.6 months. Follow-up averaged 19 months. All nonunions healed after an average of 5 months. DASH score at last follow-up averaged 15 points. Although two surgical procedures are needed, one to cure infection and another to achieve bony union, this approach for posttraumatic infected nonunions of long bones of the upper extremities represents a valid treatment alternative.