An analysis of T-cell subpopulations was carried out in the peripheral blood of 21 subjects with alopecia areata (AA) of the scalp in various phases of its evolution and in 18 healthy control subjects by means of different monoclonal antibodies of OKT series (T3, T4, T8, T11). Patients with AA in active phase showed a significant reduction of OKT 8+ cells (p less than 0.002) and a significant increase of OKT 4+ cells (p less than 0.002) versus controls. On the contrary, patients with regrowing hair showed a significant increase of circulating OKT 8+ cells compared with controls (p less than 0.002). No abnormality in the distribution of T-cell subsets in patients with AA in stable phase has been observed.