A rare but serious adverse event of total hip replacement (THR) is periprosthetic femoral fracture. The aim of the present study was to assess whether there was an excess mortality due to such a fracture and to estimate the probability of death caused by the fracture. We studied primary total hip replacement in 27,652 men and 35,930 women with osteoarthritis from The Swedish National Hip Arthroplasty Register operated from 1979 to 2000. From the same register we also studied 392 men and 344 women with periprosthetic fracture from 1979 to 2000, all with osteoarthritis as the primary diagnosis. By the special method applied, it was possible to perform the estimation of death due to the fracture event though we could not determine in the individual case whether the fracture caused the death. Compared to the total population of patients operated with a primary THR there was a higher mortality rate immediately after the surgery for patients with periprosthetic fracture and in the longer run for patients below the age of 70 years. At the age of 70 years the estimated probability of death due to the fracture was 2.1% for men and 1.2% for women. At the age of 80 years at fracture the corresponding probabilities were 3.9% and 2.2% for men and women, respectively.