In the group of 31 patients treated by immobilization of the forearm we observed 71% of secondary dislocations and in group of 46 with the full-arm plaster 65% of secondary dislocation occurred. In the group of 20 patients with the full-arm plaster and the X-ray done between the 7th and 10th day after reduction to correct possible dislocation, followed always by the new, similar plaster cast, we observed 40% of secondary dislocations. Whenever the full-arm plaster was used Sudeck syndrome was observed very rarely. No direct relationship between kind of plaster used and the degree of shortening of the radius length after healing of the fracture was found. Comminuted fractures and osteoporosis are in favour for secondary dislocations.