Takayasu's Arteritis Global Registry aims to bring a large group of patients from different parts of the world to analyse and compare the patients' demographic, clinical, laboratory, radiological and prognostic features with outcomes, approaches to diagnosis, assessment, management and therapeutic interventions in different centers. The present project provides for both a retrospective and a prospective longitudinal study. The study is designed as retrospective for patients already diagnosed with TAK and treated with available treatments. Also, the study is designed as prospective for patients diagnosed with TAK after the initiation of the Registry or the adhesion to the project. This is thought as a multicentre, international study addressed to all Centers that will want to contribute to the present project. The study is non-interventional: demographic, clinical and therapeutic data required over time are collected with the routine diagnostic, clinical and therapeutic procedures usually carried out for the optimal management of patients and according with good clinical practice.