A prospective radiological and functional assessment has been performed on 235 consecutively treated displaced Colles' fractures. The age and sex of the patients, as well as the initial displacement, involvement of articular surface and the adequacy of reduction of the fracture, were all analysed. Because of their greater potential for collapse, the better reduced fractures tended to lose more position during treatment. Despite this, in general, the better the reduction, the better was the final anatomical position of the fractures. The functional result at 3 months was related to the severity of initial displacement of the fracture and, to a lesser extent, to the anatomical result. Involvement of the radiocarpal and the distal radioulnar joints did not seem to affect adversely the patients' rehabilitation, but this was slower and less complete in the elderly. At 6 months, 60 per cent of patients had good or excellent function in the hand and wrist.