Intra-articular fractures of the distal part of the radius in young adults comprise a distinct subgroup of fractures that are difficult to manage and are associated with a high frequency of post-traumatic arthritis. The effect of residual radiocarpal incongruity after this fracture has not been investigated previously. A retrospective study of forty-three fractures in forty young adults (mean age, 27.6 years) was done to determine the components that are critical to the outcome. Treatment included application of a cast alone in twenty-one fractures, insertion of pins and application of a plaster cast in seventeen, external fixation in two fractures, and open reduction and internal fixation in three fractures. At a mean follow-up of 6.7 years, 26 per cent were rated as excellent; 35 per cent, as good; 33 per cent, as fair; and 6 per cent, as poor. There was radiographic evidence of post-traumatic arthritis in twenty-eight (65 per cent) of the fractures. Accurate articular restoration was the most critical factor in achieving a successful result. Of the twenty-four fractures that healed with residual incongruity of the radiocarpal joint, arthritis was noted in 91 per cent, whereas of the nineteen fractures that healed with a congruous joint, arthritis developed in only 11 per cent. A depressed articular surface (a so-called die-punch fragment) was reduced anatomically by closed means in only 49 per cent and was responsible for residual incongruity in 75 per cent of the incongruous joints at late follow-up. Non-union of the ulnar styloid process adversely affected the results. Restoration and maintenance (extra-articular reduction) of the dorsal tilt and radial length did not prove critical except when severe radial shortening occurred.