Of the few risk factors identified for the development of anxiety disorders, behavioral inhibition has received the strongest support. However, studies examining prediction of anxiety disorder from inhibition over time have not been extensive, and very few have assessed the impact of inhibition assessed early in life on anxiety in adolescence. The current study assessed 3 risk factors among 91 children when they were approximately 4 years of age, and determined anxiety diagnoses when the children were in midadolescence (mean age, 15 years). Children were included in the study at preschool age if they scored high (n = 57) or low (n = 34) on behavioral inhibition. Maternal anxiousness and maternal attitudes toward the child were assessed at the same time. Diagnoses at age 15 years were categorized as social anxiety disorder or other anxiety disorders. Social anxiety disorder at age 15 years was predicted by both inhibition and maternal anxiousness at age 4 years, whereas other anxiety disorders were predicted only by maternal anxiousness. Almost 37% of inhibited preschool-aged children demonstrated social anxiety disorder at age 15, compared with 15% of uninhibited children. The results support a growing body of research pointing to the importance of behavioral inhibition as a risk for social anxiety well into adolescence, and also highlight maternal anxiousness as a more general risk across anxiety disorders.