Aims: The purpose of this paper is to evaluate the effectiveness of cementless total hip arthroplasty using a threaded acetabular component with a titanium press þt stem. Methods: A total number of 179 cementless primary total hip arthroplasties was performed consecutively using a tapered rectangular gritblasted titanium press þt stem and a threaded conical titanium cup. Articulating wear partners were a ceramic ball head and an UHMW polyethylene inlay. At the time of evaluation with a minimum follow-up of 10 years 57 patients had died and 18 were not available for follow-up, thus leaving 104 consecutive, non-selected hips in 100 patients for clinical and radiographic examination after an average follow-up period of 11.6 years (range 10.0 to 14.2 years). Results: The average Harris Hip Score at the time of the latest follow-up was 88.7 (range 24 to 100). In 9 hips (5,0%) a revision was performed: in 6 cases (3,4%) the reason for revision was increased polyethylene wear. 2 cups (1,1%) were revised because of pain and radiographic signs of aseptic loosening without presence of increased wear. One hip had to be revised due to late deep infection after 7,2 years. All stem implants were rated stable. The probability of survival of both the ace-tabular and femoral component at 12 years with any reason for revision as endpoint was 94,8% (95% con-þdence interval). The survivorship with revision due to aseptic loosening of a component as endpoint was 97,7%. Conclusion: The design and material used for the threaded cup and tapered stem are decisive factors for the success of this cementless implant. With the above evaluated total hip system favourable long term results over a period of more than 10 years could be achieved.