Acetabular bone deficiencies encountered during the revision hip arthroplasties should be recon- structed to provide the implant stability and to restore the normal center of rotation of hip and the leg length. We revised the loosened acetabular cup by grafting fresh-frozen bulk femoral head and inserting uncemented cup in 17 hips of 15 patients. The average follow-up period was 2 years and 3 months. The acetabular bone deficiencies were type 2A in 6 hips, type 2B in 8, type 3A in 1 and type 3B in 2 by Paprosky's classification. Three blocks of femoral head were grafted in 3 type 3 deficiencies, but only one in type 2 deficiencies. The cup-host bone contact was 41% on the average. However, the cup-host bone contact in the zone I was present only in 12 out of 17 hips and its average was 14%. Incorporation of the allograft into the host bone occurred between 5 months and 1 year and 7 months (average, 8,6 months) after revision surgery. Significant radiographic loosening sign was noted only in 2 hips which had not only type 3B bone deficiencies reconstructed with 3 blocks of femoral head allograft but also no cup-host bone contact in zone I . The bulk allograft of fresh-frozen femoral head demonstrated acceptable results in type 2 acetabular bone deficiencies, although the follow-up period was relatively short. Reconstruction of type 3B acetabular bone deficiencies by using multiple blocks of femoral head allograft had been failed. We presumed that the lack of the graft stability and the intimate contact between the grafts and host bone was the cause of failure.