Aims: Analyse our results of the treatment of humeral shaft fractures treated solely with functional brace. Methods: The patients 16 years or more in age admitted in Tampere University Hospital because of fracture of diaphysis of the humerus between January1997 and December 2000 were included in this study. The fractures were treated solely using functional brace. Results: There were 94 closed fractures with 38 (42%) male and 52 (58%) female patients whose ages were between 16 and 90 (median 50) years in this study. The fracture configuration was spiral (A1) in 54 (60%), transverse in 31 (34%) (A3) and comminuted in 5 (6%) (C1). The fractures located in the proximal third of the diapysis of the humerus in 12 (13%), in the middle third in 57 (63%), and in distal third in 21 (23%) of the patients. From 90 fractures 69 (81%) consolidated without problems. In 6 fractures of the 12 (50%) at the proximal third, 48 of the 57 (87%), and 17 of the 21 (85%) bony union achieved using functional brace. There was significant difference with respect of consolidation between proximal and middle third (p< 0.01) and between proximal and distal third (p< 0.05) of the humeral shaft. There was no significant difference between fractures of middle and distal third of the diaphysis of the humerus. From spiral, transverse and comminuted fractures, 22of the 28 (78%), 28 of the 31 (90%), 5 of the 5 (100%) consolidated without problems using functional brace. Conclusion: The management of middle and distal third humeral shaft fractures solely with functional brace is justified. Our series indicated that consolidation is achieved also in transverse fractures, even though those fractures have often been considered as a relative indication for operation.