The past two decades have witnessed significant growth in our understanding of the developmental antecedents of anxiety disorders. In this article, we review studies of offspring at risk for anxiety disorders, longitudinal studies of the course of anxiety disorders in clinical, epidemiologic, and at-risk samples, studies of hypothesized temperamental risk factors for anxiety, and give a brief overview of the literature on environmental risk factors. Clear developmental antecedents to anxiety disorders identified include (1) childhood anxiety disorders [in particular, separation anxiety and overanxious disorder/general anxiety disorder (GAD)], (2) behavioral inhibition which predicts later social phobia, (3) anxiety sensitivity which predicts later panic disorder, and (4) negative affectivity, which predicts a spectrum of psychopathology including anxiety disorders. Further prospective studies are needed to examine the roles of environmental factors such as parenting practices, peer influences, stressful life events, and perinatal stressors. Future studies could benefit from (1) beginning earlier in development and following individuals into adulthood, (2) assessing the overlap between multiple temperamental constructs, (3) greater use of observational measures of temperament and of parent-child and peer interactions, (4) greater attention to parental psychopathology which may confound associations noted, (5) exploration of other features of anxiety disorders (neurofunctional correlates, cognitive features, other aspects of emotional regulation) as potential precursors, and (6) intervention studies exploring whether modifying developmental antecedents can alter the course of anxiety disorders.