HLA B27 and other clinical findings were investigated in 18 Turkish patients with Reiter's syndrome (mean age 35.8 +/- 8.09). Male/female ratio was 2/1. All 18 patients were seronegative, 12 (66.6%) presenting with an asymmetrical oligoarticular arthritis. Radiological sacroiliitis and enthesopathy was found in 9 (50%) and 7 (45.6%) patients respectively. HLA B27 was present in 11 (61.1%) patients.