The prevalence of rheumatic diseases was studied in representative subsamples by interview (n = 134), and by physical (n = 89) and radiographic (n = 81) examination in a representative sample of 79-year-olds in Göteborg, Sweden. The prevalence of rheumatoid arthritis (3-8 ARA criteria) was 10%. Radiographic osteoarthritis (OA) was diagnosed in wrists and/or finger joints of 65% of the probands and in knee joints of 14%. The first metacarpophalangeal (MCP I) joint was more frequently involved in males than in females (p less than 0.05). In females palpable enlargement of distal (DIP) and proximal interphalangeal finger joints correlated (p less than 0.01) to radiographic OA. The degree of heavy work in previous occupations was correlated to radiographic OA of DIP II-V in females (p less than 0.05 and of MCP I in males (p less than 0.05) but not to radiographic or clinical OA in knee joints. Symptoms of OA were reported by 6.1% in the knee and in 4.5% in hip joints. The prevalence of chondrocalcinosis averaged 15% (23% of females and 6% of males). Chondrocalcinosis of the hands occurred in 21% of females but in no males. The prevalence of hyperuricemia was 15% (women 6%, men 29%), and gouty arthritis was found in one woman.