The Diagnostic Interview Schedule was used to identify 89 incident social phobia cases in wave 2 household subjects from 9437 at risk persons age 18 or older as part of the Epidemiologic Catchment Area study. Crude annual incidence of Diagnostic Interview Schedule/DSM-III social phobia was estimated at 9 per 1000 population per year. Onset of social phobia was associated with low education, never having been married and female gender. First onsets occurred throughout the life course of this adult sample. Nervousness, headache, panic spells, palpitations, other phobias, binge pattern of alcohol consumption, dysthymia and schizophrenic symptoms were also predictive of social phobia onset. There was no difference in predictive factors when "primary" social phobia (without premorbid panic) was analyzed separately.