The ankle is one of the most common site of ligamentous injury. The incidence of the injury is increasing in these days, probably due to prevailing leisure and sports. Lateral collateral ligament is more susceptible to injury than medial because of anatomical and biomechanical difference. There was a tendency to treat the ankle ligamentous injury with conservative method, but because of the problem of chronic and recurrent ankle instability and injury, operative method is necessary in certain patients. We have experienced of 14 cases of surgical treatment of the lateral ligaments, excluding the associated fracture, from March 1983 to February 1986, in Koryo General Hospital. Among 14 cases, the acute injury, which were treated with primary repair, were 9 cases and the chronic cases, which with modified Watson-Jones method, were 5. The average follow up period was 1 year and 2 months. The results are as follows : 1. The male and female ratio, was 9 to 5 and peak incidence was 3rd and 4th decade. 2. The cause of injury was mainly slip down (9 cases) and sports injury(4 cases). 3. There was no correlation between the degree of the ligament rupture and talar tilt. 4. When the talar tilt is above 10, it may cause ankle instability. 5. The clinical results are both satisfactory in acute and chronic cases, but in chronic cases, some degenerative changes began to appear in 2 cases. 6. C.P.M.(Continuous Passive Motion) and Air Cast have much advantages in postoperative care.