To develop a Romanian version of the Bath Ankylosing Spondylitis Functional Index (BASFI) and to determine its metric properties in patients with spondylarthropathies (SpA).A Romanian version of BASFI was obtained after translation, back-translation and pretesting. Altogether 41 SpA patients fulfilling the ESSG criteria were included, 34 of them satisfying the modified New York criteria for ankylosing spondylitis. BASFI was completed by the patients along with assessment of clinical and disease activity variables by both the patient and physician. Scalability, internal consistency, reliability and construct validity of the Romanian BASFI were assessed.Mean time to complete the questionnaire was 2 minutes. Scalability (0.2-9.7, 95% of the scale), internal consistency (Cronbach's alpha = 0.93), reliability (intraclass correlation coefficient = 0.82) and construct validity (correlations (absolute value(r) = 0.37-0.59) with spinal pain, nocturnal pain, patient's and physician's global assessment, fingers-to-floor distance, occiput-to-wall distance, modified Schober test, intermalleolar distance, and Dougados articular index) were all very satisfactory.Translation and cultural differences did not alter the well-known value of BASFI. Therefore, the Romanian version of BASFI is reproducible and valid for the assessment of patients with spondylarthropathies.