Volar percutaneous cannulated screw fixation of acute scaphoid waist fractures reportedly produces high rates of healing and early return to work, but the method has not been reported for treating scaphoid waist delayed unions. We therefore report the surgical results of percutaneous screw fixation in scaphoid waist delayed union in 12 patients. All patients were male with an average age of 31.1 years. Duration of injury was 12 weeks (range, 6-20 weeks). However, no patient had carpal instability, scaphoid deformity, or avascular necrosis of the proximal fracture fragment. The minimal followup was 12 months (mean, 20 months; range, 12-24 months). Preoperative radiographs showed slight bone resorption at the fracture site in five patients and cyst formation in three patients. A cannulated screw was introduced volarly under image intensifier guidance in all patients. All fractures united uneventfully. At 12 month followups, the flexion and extension arcs of the injured wrist were 94% and 93% of the uninjured wrist. Grip strength averaged 34 ± 3 kg, which was 92% of the grip strength of the uninjured hand. The Mayo Modified Wrist Score was 94 ± 6 points and the Disabilities of the Arm, Shoulder, and Hand score was 9 ± 6 points. Our experience suggests volar percutaneous screw fixation is a reliable method to treat scaphoid waist delayed union. Level of Evidence: Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.