Introduction. The study presents a new method of hip joint acetabular reconstruction performed in the course of the primary cementless endoprosthesoplasty. Material and methods. The method involves using the autogenic femur head to fill the defect on the „dovetail” principle instead of simply screwing its fragment to the side of the deformed acetabulum. One part of the graft fills the roof while the other part is placed in the acetabulum where the proper bony acetabulum is reconstructed. This method offers the possibility to reconstruct the pivoting point of the joint and prevents the migration of the implanted endoprosthesis. 42 patients were treated in this way, their average age being 51 (from 24 to 84). The study presents the surgical technique and the results of the treatment, evaluated on the basis of clinical and radiological examination. Conclusions. The average observation period was 5.3 years (from 2 to 9 years). In 1 case loosening of the cementless acetabulum of the press-fit type was observed, and in 1 case a clearing around the acetabulum not exceeding 2 mm was reported, without clinical symptoms during a 3-year observation period. The remaining patients scored 84 points in the Harris scale, i.e. a very good or good result. No results denoted as „sufficient” were recorded. In the WOMAC scale 90% of very good and good results were obtained. Our research confirms the advisability of this type of reconstruction.