At present, femoral head saving surgery is reserved for femoral neck fracture patients who are either young or have suffered a minimally displaced fracture. However, even after this strict selection, an approximate failure rate of internal fixation of 15% is described in the literature. The present study looked if failures can be discerned from successes by baseline differences. Files and X-rays of 164 consecutive femoral neck fracture patients treated by internal fixation in our hospital between 1996 and 2002 were studied, retrospectively. Successfully treated patients and failures (defined as the need for an arthroplasty following internal fixation) were compared with regard to patient’s age, pretraumatic mobility, fracture dislocation, fracture angle, operative delay, operative duration and experience of the surgeon. Of the 164 patients undergoing internal fixation for a femoral neck fracture, 16 were classified as failures (10%) and 148 were treated successfully. There was no statistical difference between groups with regard to any of the studied variables. Patients in whom internal fixation of femoral neck fractures fails, cannot be discerned from successfully treated patients by preoperative variables.