Social Anxiety Disorder (SAD) is the third most prevalent condition among psychiatric disorders, which has a chronic and disabling course and is highly associated with comorbidities. The onset of SAD is early and its diagnosis is underestimated by both mental health professionals and the patients themselves. A growing interest in the study of this disorder has been observed during the last decade, regarding its clinical, diagnostic and/or treatment aspects. The objective of this book is to present the scientific advances related to SAD obtained in studies by a group of Brazilian investigators involving rating and screening instruments, epidemiology, association with psychiatric comorbidities and other general medical conditions, neuroimaging, social skills and functional impairment, current parameters of pharmacological treatment, and studies involving new medications. The book is directed at students and professionals in the mental health area, and to professionals who act in the area of health prevention.