In the period from January 1980 until December 1990 we treated 147 children and adolescents with supracondylar humerus fracture, and followed the outcome in 127 of them. Three (2.4%) patients had no displacement of fractured bones and were treated only with plaster cast immobilization. Twenty three (18.1%) underwent closed reduction of fragments and application of a plaster cast. The majority (97; 76.4%) required manual reduction and the fixation of segments with Kirschner's wires laterally and medially. Four (3.1%) patients were treated with open reduction and fixation with Kirschner's wires. Both plaster cast immobilization and fragment fixation with Kirschner's wires lasted only 14 days and were immediately followed by rehabilitation. Such a short immobilization of extremities or fixation offragments did not result in any complication. Of 56 children available for long-term follow-up, we achieved excellent treatment results in 43 (76.6%) of the patients, good and fair in 12 (21.5%), and a poor result in only 1 patient (1.8%). There were no permanent vascular or neurological complications apart from slight weakness of the ulnar nerve in 3 patients. In conclusion 14 days seemed to be the biological minimum of time needed for this type offracture to heal in children and adolescents. Fixation of the fragments with Kirschner's wires and immobilization of the extremity for only 14 days brings a significant reduction of total treatment expenses, avoids repeated x-ray examination, facilitates early physical therapy and returns the child to its family.