The purpose of the study was to analyse the occurrence of the third trochanter and its correlation with the morphology of the human femur. The third trochanter was found in 38 of 622 (6.2%) human femora taken from 3 excavation sites. 36 of these were included in the study and were compared to the femora without the third trochanter. The bones with the third trochanter were characterised by a greater superior sagittal diameter and diaphysis platymetry index as well as a larger greater trochanter. These results suggest that the third trochanter is not a progressive morphological feature of the skeleton. Rather it is connected with an altered gluteal muscle function.