We analyzed prospectively the 5-year survival in 926 patients undergoing 1,024 total knee arthroplasties (TKA) in the period February 1989-December 1990. The patients were compared to an age- and sex-matched general population and to 326 patients operated on in the same period with total hip arthroplasty. Cox analysis showed that male sex, rheumatoid arthritis and complications within the first year increased the mortality rate in the TKA group. When this group was compared to the general population, only rheumatoid patients aged 65-74 years had an increased mortality. Generally, the TKA patients had a longer survival than the general population, especially women > 75 years old with arthrosis. The cumulative 5-year patient survival was 89%, both after hip and knee arthroplasty and was 81% in the matched general population.