PURPOSE: There is rare report about screw length in ankle fracture in spite of the anatomical characteristic that distal densest area can give enough purchase of screw threads for fixation of medial malleolar fragment. Purpose of the current study is to evaluate the results of screw fixation and to estimate proper screw length in medial malleolar fracture. MATERIALS AND METHODS: Authors retrospectively reviewed 136 cases of medial malleolar fracture which had been performed from Janurary 1985 to December 1997. The patients were divided into 3 groups according to screw length ; under 34mm screw length (9 cases), between 35mm and 45mm (76 cases), over 46mm (50 cases). Each group was evaluated bone union time, clinical outcomes and radiological results by Meyer and Kumler. RESULTS: Good and excellent results were achieved 121 cases (89%) on clinical result and 125 cases (91.9%) on radiological result by Meyer criteria. There were no statistical differences between three group, but the 35mm-45mm screw length group showed slightly faster union tendency. CONCLUSION: In the treatment of medial malleolar fracture, around 40mm length screw is sufficient for fixation and it doesn,t need to use the screw over 45mm length for more rigid fixation.