Total hip replacement is often recommended for the treatment of femoral neck fractures in elderly patients. A less invasive approach with shorter operating time is the replacement of the femoral head only, leaving the acetabular cartilage in situ. Hemiarthroplastic hip replacement using a metallic head prosthesis was not successful in the past, because the majority of patients developed protrusio acetabuli after surgery. In the present study hemiarthroplastic hip replacement using an Al2O3-ceramic head was shown to be a useful method for the treatment of femoral neck fractures in elderly patients. From 1985 to 1990 277 patients were treated with hemiarthroplasty. The average age at the time of accident and operation was 81.7 years. At the time of follow-up in 1993 only 77 survivors were available for examination. A standardized score was calculated assessing activity, gait, hip pain, etc., with the patients obtaining an average score of 58 out of possible 78 points. Only three patients had hip pain, and in four cases the roentgenographic examination revealed protrusio acetabuli. Two of these four patients underwent revision surgery for replacement of the cup, leaving the stem in situ. In view of the small number of approach-related complications, hemiarthroplastic hip replacement using an Al2O3-ceramic head is the recommended surgical treatment for femoral neck fractures in elderly patients. In the rare patient with protrusio acetabuli, revision surgery can be performed to replace the cup, leaving the stem in situ.