OBJECTIVE: To describe the role of the Assessment of SpondyloArthritis interntational Society (ASAS) over the past 30 years in the understanding of the field of spondyloarthritis. METHODS: A narrative review of the achievements. RESULTS: A summary of the role of ASAS in defining nomenclature, definition of and criteria for SpA, outcome assessments, recommendations, and education. CONCLUSION: ASAS played an important role in shaping the field of SpA.