The role of general and suppressor T-cell function was investigated in a group of twelve children with atopic asthma and ten non-atopic control children. Studies of active E rosettes, lymphocyte stimulation, and delayed type skin responsiveness revealed no statistically significant group differences. Data obtained employing a concanavalin A-induced, suppressor T-cell assay revealed that the asthmatics generated significantly less suppressor cell activity than did the normal control group. There was no correlation between lack of suppressor cell function and serum IgE levels. The results of this study support the concept of suppressor T-cell dysfunction in atopic disease.