The authors compared 137 adult patients who had agoraphobia with 81 patients who had either simple or social phobia for a history of childhood and adolescent separation anxiety. Female agoraphobics reported significantly more childhood separation anxiety than female combined simple and social phobics; males showed no significant difference between diagnostic groups. The reported prevalence of separation anxiety in adolescence was relatively low, but agoraphobics of both sexes reported significantly more separation anxiety than combined simple and social phobics. There were no significant differences between groups for parental losses or severe family disruption during childhood. The results suggest that childhood separation anxiety is a risk factor in females but not in males for the later development of agoraphobia.