Anterior Uveitis is the most common form of uveitis. There are several known and many possible etiologies for anterior uveitis. After examining the posterior segment and ruling out masquerade syndromes, the main step of etiologic diagnosis is clinical characterization. It is essential to establish the presence or absence of unilateral versus bilateral and granulomatous features. Subsequently, a directed work-up may be obtained which then helps to confirm diagnostic hypotheses based on the detailed history and clinical examination. The priority is to rule out an infection. Treatments are adapted according to etiology and disease severity. Finally, biologics have greatly changed the management and prevention of some forms of anterior uveitis, in particular uveitis associated with HLA-B27 and juvenile idiopathic arthritis-associated anterior uveitis.