Damage to the collateral ligaments of the ankle is relatively common, particularly the lateral ligaments; therefore, it is important to be aware of the detailed anatomy and frequency of variation of the individual ligaments. Only two reports of collateral ligaments dimensions were found in the literature, neither of which considers all of the individual components of the collateral ligament complex. Osteoligamentous preparations of the collateral ligaments of 40 ankles from 20 cadavers of European Caucasian origin were studied, from which mean values for the length and width of the individual components were determined, together with their frequency of occurrence. For the collateral ligaments of the ankle as a whole, the ligamentous dimensions determined in this study are similar to those reported previously. The data presented in this study are, therefore, a valuable addition to the small pool of data that exists concerning the dimensions of the collateral ligaments of the human ankle joint. These data may be of value when considering surgical repair or reconstruction of traumatized collateral ligaments, especially because any undue foreshortening of the ligaments may reduce the range of motion possible at either the ankle or subtalar joints, or both. It is possible that in extreme cases, such a reduction in the range of motion may modify gait patterns and the transmission of stresses across the joints of the foot and lower limb.