OBJECTIVES: To describe indirect resource utilization for inpatient ankylosing spondylitis (AS) patients treated in tertiary public health facilities over a 1-year period in Turkey, and demographic factors and disease activity scores associated with indirect costs. METHODS: Medical records of 650 prevalent AS patients attending seven centers at tertiary healthcare institutions nationwide were examined to assess annual indirect healthcare costs. Eligible patients were age ≥18 and diagnosed with AS for at least 12 months. We assessed relevant indirect cost-related variables and activities, and actual costs. Multivariate regression was used to determine the effects of demographic factors on indirect costs. The Pearson correlation matrix and the association between disease activity scores and indirect costs were assessed. RESULTS: Average AS patient age was 40.1± 11.33 standard deviation (SD) years and 35% of patients were female. 55% were employees, of which 59% had employer permission to miss work (average 17 days annually) due to AS, costing patients an average €412 annually due to workday loss as calculated based on income level. 2% of patients had other AS-related consultations not covered by insurance (acupuncture, homeopathic, other), bringing their average annual burden to ª2,482. 10.46% of AS patients incurred additional AS-related costs (e.g. need for new car, apartment, special equipment), spending an additional ª1,978 per year. 6.92% of patients required caregivers, costing €546 annually. Multivariate regression showed that age and gender played no significant role related to the increase in indirect costs. Patients needing AS related equipments reported significantly higher Global Disease Activity (GDA), visual analog scale (VAS), Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) and lower EuroQoL health status (EQ-5D) scores. CONCLUSIONS: AS represents a considerable economic burden to Turkey. Studies assessing chronic disease costs, especially in developing nations, are important to determine efficient allocation of the limited resources in such regions.