Behcet disease is currently considered an "autoinfiammatory disease" triggered by infection and environmental factors in genetically predisposed individuals. Although the disease is characterized by recurrent oral and genital aphthous ulcers and ocular involvement, it can affect multiple organ systems. Complex aphthosis is characterized by recurrent oral and/or genital aphthous ulcers. It is important to evaluate the patient with complex aphthosis for Behcet disease and related systemic disorders. We discuss the etiopathogenesis, clinical features, diagnostic criteria, and treatment approaches for complex aphthosis and Behcet disease in light of the current literature. (C) 2017 Elsevier Inc. All rights reserved.