We treated 26 cases(25 patients) olecranon fractures operatively with Kirschner wire and tension band wiring technique from January 1993 to December 1995. The Kirschner wire fixation methods in our study were either bicortical fixation(15 cases) or intramedullary fixation(11 cases). We retrospectively reviewed clinical results according to Mayo elbow performance index and starting time of full range of motion(ROM) exercise. We analyzed relationship between the cli9nical results of the cases with cast immobilization and those without cast immobilization. We also compared Kirschner wire fixation methods in the respect of clinical results, full ROM exercise starting time and complications. The results were as follows. 1. Clinical results were excellent or good in 25 cases(96%) according to Mayo elbow performance index. Full ROM exercise starting time was within 2weeks in 10 cases, between 2-3weeks in 11 cases, between 5-6weeks in four cases and after 6weeks in one case. Full ROM exercise starting time was significantly different(P=0.016) with clinical results statistically and there was statistically high significant difference(P=0.0025) between clinical results and cast immobilization or not. 2. Clinical results of bicortical fixation group was ont significantly different frmo those of intramedullary fixation group and there was no significant difference between full ROM exercise starting time and Kirschner fixation methods statistically. 3. The most frequent complications were decreased ROM and loosening of the Kirschner wire. There were decreased ROM In 10 cases and loosening of the Kirschner wire in 6 cases in all cases. We encountered more higher incidence of complications related to intramedullary fixation method. The clinical results and full ROM exercise starting time of bicortical fixation group were not significantly different with those of intramedullary fixation group statistically. But more early exercise, more better clinical results and more less complications was produced in bicortical fixation group. So we thought bicortical fixation method is better than intramedullary fixation method.