Objective: To determine the clinical, labo examination and cause of ankle arthritis not due to trauma. Patients and methods. 182 patients with ankle arthritis who were diagnosed and treated at the Rheumatology department, Bach mai Hospital in 5 years (from June 2006 to June 2011). Clinical manifestation, labo test were collected. Results: 182 ankle arthritis patients with mean age 37.5+13.7, most of them were male (73 percent) with main clinical and labo manifestation such as: pain (100 percent), inflammation (95 percent), movement limited (68 percent), increasing erythrocyte sendimentation rate (74 percent), high protein C reactive (74 percent), 53 percent patients with xray involved. The common reasons of ankle arthritis were tubeculosis arthritis (22.5 percent) and joint infection (18.5 percent), there was 10.9 percent patients undiagnosed. Conclusion. There are still have many problem in diagnosis of patients with ankle arthritis without trauma in clinical practive.