Thirty-nine patients, who had received a fracture of the olecranon at an average age of 7.4 years, were reviewed at an average age of 32 years, in order to evaluate the results of treatment. All patients had reached skeletal maturity at follow-up. Thirty-four fractures were treated conservatively and five, surgically. Of the 34 fractures treated conservatively, six also had surgical treatment of associated fractures. We identified five patterns of fracture on the basis of the anatomic site of the fracture line, the interfragmentary displacement and the presence of an associated lesion. According to our grading scale, 34 patients had a good result, two a fair result and three a poor result. We observed poor results in only 7.6% of cases, even though 85% of the patients had received an intraarticular fracture. We believe that the long-term prognosis of olecranon fractures in children is related to the anatomic site of the fracture line, to the interfragmentary displacement and to the presence of an associated lesion. Conservative treatment may be indicated when the interfragmentary displacement is less than 2 mm. The presence of an associated lesion is a negative prognostic factor.