Zinc is an trace metal necessary for T cell differentiation and maturation. Forty-two patients, with Aids Related Complex or malignancy in remission and with severe and stable CD4 lymphoid cells cytopenia were submitted to zinc gluconate, 125 mg twice daily orally for three weeks. Reevaluation of T cell subsets one week after the end of zinc intake showed non significant modification of total lymphocyte counts nor of CD4 subsets. CD8 cells however were significantly increased in absolute number in those patients with initially low counts of the cells while they were significantly reduced in those patients with initially normal or high CD8 cells counts. Zinc gluconate in short courses appear to act as a regulator of CD8 lymphoid cells subsets.