PURPOSE: In the treatment of an unstable intraarticular distal radius fracture, we report the result of a retrospective study of reduction maintaining effect of external fixation. MATERIALS AND METHODS: During the period from May 1996 to May 1999, 19 patients 20 cases with AO type C2, C3 distal radius fracture were treated by external fixation and followed-up for 2 years or longer. Six had AO type C2 fracture, and fourteen type C3. We evaluated immediate postoperative & follow-up radiological evaluation by volar tilt, radial inclination, radial length difference. As combined treatment, additional reduction maintaining effect of bone graft or internal fixation was evaluated also. RESULT: Mean reduction loss of 2 years or longer follow-up after external fixation was volar tilt 7.2 degrees, radial inclination 4.3 degrees, radial length 3.1 mm. As additional reduction maintaining effect, internal fixation had statistically significant effect(p <0.05)-especially radial length maintenance, but bone graft not significant. CONCLUSIONS: In unstable intraarticular distal radius fracture, after open reduction or bone graft etc. for intraarticular anatomic reduction, we consider external fixation or combined internal fixation for reduction maintenance.