In the 3 decades since Liebowitz's review of ‘a neglected anxiety disorder,’ controversy and challenges have remained in the study of social anxiety disorder (SAD). This review examines evidence around the classification and subtyping of SAD, focusing on generalized SAD. Substantial discrepancies and variation in definition, epidemiology, assessment, and treatment of generalized SAD exist as the international literature on it has grown. In East Asian cultures in particular, study of taijin kyofusho has been important to a broadened conceptualization of SAD into generalized SAD. Despite important progress with biological and other studies, many challenges in the understanding of generalized SAD will remain in the years to come.