Social phobia is a common, highly comorbid, poorly understood and relatively understudied condition. The origins of social phobia share familial and biological features common with those of other anxiety disorders, but seldom have precursors of the fear of social communication been examined as a possible pathway to social phobia. Here we examine the role of early childhood language impairment as an antecedent to social phobia in late adolescence. Participants in a prospective longitudinal community study identified as having language impairment at age 5 and matched controls were followed up at age 19. Compared to normal language controls, individuals with a history of early language impairment had 2.7 times the odds of having a social phobia by age 19. Results suggest that early language impairment represents a distinct pathway to late adolescent social phobia.