Ankle arthrography, by direct puncture of joint cavity, is considered to be a simple and accurate diagnostic method for a precise evaluation of ligamentous injury. Forty-seven cases of ankle arthrography were successively performed in the patients of acute ankle sprains. The purpose of this study is to demonstrate how ankle arthrography can delineate the pathologic anatomy in such cases. The results are as follows: 1. Thirty cases among forty seven revealed the findings of ligament tears. 2. For better diagnostic accuracy, the arthrography should be performed within 72 hrs. after injury. 3. The anterior talofibular ligament tears were the most common (twenty-nine cases) of all and seventeen of them revealed tears without association of any other ligament tears. 4. There were ten cases of calcaneofibular ligament tears and nine of them were associated with anterior talogibular ligament tears. 5. Three cases of anterior tibiofibular and one deltoid ligament tears were demonstrat d.