PURPOSE: To determine the problems of anterior external fixators in unstable pelvic ring injuries. MATERIALS AND METHODS: We reviewed 25 patients with an unstable pelvic ring injuries who had been treated with only anterior external fixator over one year follow-up. By Tile's classification, type B 14, type C 11 and the radiological results were evaluated preoperation, postoperation and bone union state. The clinical evaluation was done in termas of the residual pain, discrepency in limb length, rotational deformities, gait disturbance, neurologic deficiency. RESULTS: In 25 patients with an unstable pelvic ring injuries, 18 (72%) patients were reducted and 3 (17%) patients of 25 were reduction failure at last follow up, they were all Tile type C. The residual pain was graded normal 3, mild 11, moderate 10, severe 1 respectively. The cases with discrepency in limb length and gait disturbance were 6 (all type C), 10 (type B 3, type C 7) respectively. The complication were 4 pin site infection, 3 pressure sore and 1 pyogenic hip arthritis. CONCLUSION: Our results indicate that anterior external fixator should be limited to vitally unstable patients in acute resuscitative phase and cases without vertical displacement.