||The estimation of sex is a vital step in the osteological analysis of adult human remains. The methods available for this purpose generally rely on the presence of a well-preserved pelvis or cranium. However, these bones are not always available. Other skeletal elements have successfully been used for this purpose. In this thesis, the sexual dimorphism of the proximal femur in a post-medieval Dutch population is assessed using seven different measurements: femoral neck width (FNW), femoral neck axis length (FNAL), trochanter-diaphysis distance (TD), greater-lesser trochanter distance (TT), greater trochanter width (TW), trochanter-head distance (TH) and the vertical head diameter (VHD). The sample, from the predominately 19th century Middenbeemster site in the Netherlands, consists of 68 individuals and includes 50 individuals with known-sex and known age-at-death. Additional to the assessment of sexual dimorphism, a sex estimation method was chosen and tested for accuracy. The C5.0 algorithm was used to generate a decision tree predicting sex. The results show that all measurements studied are sexually dimorphic and are easily reproduced with low intra- and interobserver error. Furthermore, left and right do not differ significantly. An unexpected result is that age had a statistical correlation with measurement size. This is a topic that needs further research. Lastly, the sex estimation method did not yield sufficiently accurate results (62.4% accuracy) but a newly generated decision tree gained a better sex allocation accuracy of 85%. To conclude, this thesis supports that the sexual dimorphism of the femur is valuable for sex estimation of adult skeletal remains, especially when more sexually dimorphic elements of the skeleton are not accessible for analysis.