The effect of hot taste preference on selected immune responses was investigated in human peripheral immunocompetent cells. Human lymphocytes and natural killer(NK) cells were prepared at a concentration of 2$ imes$$10^{6}$ cells/ml in RPMI-1640 containing 10% fetal bovine serum. Lymphocytes proliferation was determined with the [$^{3}H$]-thymidine pulse for 18hrs after concanavalin A, phytohemagglutinin, Salmonella typhimurium mitogen, or media alone. NK cell activity was measured by cytolysis of $^51Cr$-labeled target cells K562. Serum antibodies levels such as IgM, IgG, IgA were also measured by ELISA method. There was no difference of serum IgM level among the groups, but IgG and IgA levels were greater in the group with hot taste preference than those of the group without hot taste preference. In lymphocytes of the group with hot taste preference there was a greater mitogen-induced lymphocyte proliferative responses compared to the group without hot taste preference. In addition, NK cell activity in group with hot taste preference was lower than that of the group without hot taste preference. These results suggest that the eating habit of spicy food containing hot components may affect immune status by modulating selective immunocompetent cells function.