We studied the late outcome of 40 ankles (from a consecutive series of 42) treated by a modified Evans procedure. The peroneus brevis tendon was used to fashion a static tenodesis. All the patients had suffered from persistent lateral instability following an ankle sprain. The follow-up period was between nine and 12 years. Excellent or good results were achieved in 33 ankles (82.5%), three had a fair result, and four were poor. The clinical results were matched by the radiographic results which showed significant talar tilt or anterior talar translation in only three ankles. The functional result showed no positive correlation with the stress-radiographic analysis. We concluded that this modification of the Evans operation gives satisfactory long-term results, which show little change from the good results at 24 to 35 months reported in an earlier paper from our department.