A total of 340 patients treated in the Intensive Care Unit of the Department of Orthopedics and Traumatology at Helsinki University Central Hospital were analyzed in this study. They had in all 1,071 fractures and luxations of the pelvis and extremities, of which the trauma surgeons and radiologists on duty initially missed 45 injuries, i.e., 4.2%. Taking into account the eventual late symptoms, the most severe delayed diagnoses were of injuries located around the hip and knee joints. The patients with delayed diagnoses were, on the average, the most severely ill: their needs for primary blood transfusions and assisted respiration resembled the needs of patients who later died of their trauma or its complications. The most common causes of the delay in diagnosis were: radiographs not done in 60% of patients, and no notation of visible injury in radiographs in 31%. Inferior quality of radiographs, unnoticed radiologists' reports, a fracture visible at the outermost corner of a radiograph, a fracture hidden by other fractures, or excessive obesity of the patient may also contribute to a delay. The study presents measures for improving diagnostic strategies, but it would appear that delayed diagnoses cannot be totally eradicated.