OBJECTIVES: To explore the direct health care resources associated with ankylosing spondylitis (AS) in Turkey, and establish how treatment intensity, proxied by AS treatment expenditures, affects disease activity. METHODS: Medical records of 650 prevalent AS patients attending seven centers at tertiary health care institutions nationwide were examined to assess the annual direct health care costs. Eligible patients were age ≥18 and diagnosed with AS for at least 12 months. To identify direct costs, overall costs were categorized as inpatient, outpatient, pharmacy and copay. Generalized linear models were used to determine factors affecting annual health care costs.  Costs were adjusted by exchange rate of €1= 2.30 Turkish Lira.  RESULTS:  The average patient age was 40.1± 11.33 standard deviation (SD) years and 35% of AS patients were female. Average disease duration was 7.9 years and more than 25% of patients suffered from at least one comorbidity. 7.54% of AS patients received inpatient care, 92.77% received outpatient care and 95.23% weAre prescribed at least one medication. 66.77% of patients were prescribed disease-modifying anti-rheumatic drugs (DMARDs). The mean (median) annual cost per patient was €6,059 (€6,825). The most significant portion of overall expenditures was due to drug cost (€5,728), while outpatient costs totaled €254 and inpatient costs €68. Copayments were relatively low at €12.3. Age and gender had no effect on annual health care costs. 54.92% of AS patients experienced work loss due to their condition. On average, annual cost due to work loss was calculated at €412. Two percent of patients also had other AS-related consultations, which were not covered by insurance. The average annual burden for these patients was €2482. CONCLUSIONS: Inpatient and outpatient costs for AS patients are lower in Turkey relative to other European countries. Treatment intensity inversely affects GDA, indicating that GDA can be improved by increasing treatment intensity.