In a prospective study, 38 patients with so-called "wrist sprains" and a clinical nonradiological diagnosis of scaphoid fracture were immobilized in a plaster cast for 2 weeks. At 2 weeks, six patients were found to have a complete fracture of the scaphoid through the waist. In view of this high incidence (15.8%) of occult scaphoid fracture, it is once again suggested that all cases of wrist sprains where scaphoid fracture is suspected be immobilized for a 2-week period.