A method for selecting a femoral implant based on models of a femoral neck and/or a femoral head of a patient, includes: a) detecting reference points on the femoral neck and/or femoral head of the patient; b) registering the femoral neck and/or femoral head based on three-dimensional reference point spatial positions of the detected reference points; c) producing a femoral neck model and/or femoral head model from the three-dimensional reference point spatial positions; d) ascertaining a base size of a femoral implant model based on the femoral head model; e) producing a femoral implant model based on the base size of the femoral implant model; f) positioning the femoral implant model at a position in or on the femoral head model; g) ascertaining an implant value that indicates how many or what proportion of the ascertained reference point spatial positions are outside the femoral implant model; h) determining if the implant value exceeds a predetermined limit value; and i) if the implant value exceeds the limit value, repositioning the femoral implant model and performing steps g) to i), or if the implant value does not exceed the limit value, determining an appropriate size and position of the femoral implant.