Twenty-three patients with reactive salmonella arthritis were treated at the Departments of Medicine (in 1970-1984) or at the Outpatient Department (in 1980-1986) of Meilahti Hospital. Nine different salmonella species were implicated as triggering factors. Salmonella was detected in 74% of the patients by stool cultures. Widal test was positive (greater than or equal to 1:160) in the remainder. The acute clinical picture was that of oligo or polyarthritis. Other musculoskeletal and inflammatory symptoms were frequent. The mean duration of the acute arthritis was 4.7 months (range 1.5-6.0). In 4 patients the disease ran a chronic course. The treatment of salmonella infection with chemotherapy had no obvious effect on the duration of the arthritis. In conclusion, salmonella arthritis is a form of seronegative spondyloarthritis, with acute features common to other types of reactive arthritides. The search for Salmonella should be included in the study of a patient with acute arthritis. Serology can be of help in patients with negative bacterial cultures.