The participants all met DSM-III-R criteria for current cocaine dependence. The research excluded those with current dependence on another substance other than nicotine or caffeine, those who were psychotic, and those who were medically unstable. Twenty-two of the 158 persons met the DSM-III-R criteria for lifetime social phobia. The social phobia group was compared with 22 individuals matched for age and gender. Results revealed that the individuals with both social phobia and cocaine dependence were more likely than the others to have additional psychiatric diagnoses and greater symptom severity, to be polydrug users, and to have developed alcohol dependence at an early age. Findings indicated that the prevalence of social phobia in cocaine-dependent individuals was similar to that in the community and that persons with both cocaine dependence and social phobia were more likely than those with only cocaine dependence to have several other problems. Findings indicated that these parameters should be assessed when treating this comorbid population, that social phobia occurred before the onset of cocaine dependence, consistent with the self-medication hypothesis, and that earlier diagnosis and treatment of social phobia is needed. Tables and 17 references (Author abstract modified)