Objectives. The Swedish National Total Hip Arthroplasty Register, initiated in 1979, describes the epidemiology of total hip replacement (THR) in Sweden. The objective of this study was to describe the epidemiology, demographics and to perform an outcome analysis on patients, younger than 55 years, who underwent a total hip replacement in Sweden between 1992–2002. Methods. From the Swedish National Total Hip Arthroplasty Register 11579 patients, younger than 55 years at the time of surgery, were identified who had undergone a primary total hip replacement from 1992–2002. The patients selected were checked with the Swedish Cause of Death Register (CDR), based on the unique identification number used in Sweden, to ensure that only living patients were addressed. Epidemiological and demographical analysis was then performed using SPSS (SPSS Inc, Chicago, IL). Outcome. 11362 patients were identified. 5260 (46,3 %) men and 6102 (53,7 %) women, the mean age was 48, 2 years (14–55). The indication for surgery was in over 60% of the cases Osteoarthrosis (OA) but over-represented diagnosis, when compared to the remaining THR operations in Sweden, were arthritis, osteonecrosis and sequele after childhood disease. The most common fixation technique used was cemented total hip replacement in 6160 (54,2 %) followed by Hybrid 2442 (21,5 %) and uncemented 2235 (19,7 %) technique. Survival for cemented, uncemented and hybrid implants in male patients with Osteoarthrosis after 10 years was 65,8 % (+/− 2,6%), 66,6 % (+/− 2,9%) and 64,0 % (+/− 3,0 %) respectively. In the arthritis group the survival was slightly better with a 10 year survival of 72,8 % (+/− 3,6%), 66,8 % (+/− 5,9%) and 71,5 % (+/− 7,5%) respectively, male patients had a slightly inferior outcome compared to females across all diagnosis groups. Conclusions. This young cohort is epidemiologically and demographically different than the older one previously studied in the Swedish National Hip Register. Survival analysis shows that 10 year survival in this population is considerably worse than for the older cohort. Patients with arthritis fare better than patients with Osteoarthrosis and females have superior outcome to males. In this study the mode of implant fixation did not appear to influence survival in patients with OA, however it does seem to affect the outcome in patients with inflammatory arthritis. This study shows that the outcome in this patient category is poor when compared with the older THR patients. There is an obvious need to increase use of alternative and conservative methods in treatment of the young patient with degenerative hip disease. Continuous research and referral of the young patients to dedicated centres is recommended.