A hangover is the syndrome of physical and mental symptoms that occurs 8 to 16 h after alcohol consumption with a zero level of alcohol. The aim of the current study was to investigate the effects of the alcohol hangover on cytokine production in healthy subjects. The hangover state was defined as 13 h after drinking 1.5 g/kg of alcohol (blood alcohol level=0). A venous blood sample was taken from 20 healthy adult men before consumption of alcohol and during the hangover state. Peripheral blood mononuclear cells were separated and stimulated with phytohemagglutinin. An enzyme-linked immunosorbent assay was used to measure the production of the following cytokines: interleukin (IL)-1beta, IL-4, IL-6, IL-10, IL-12, interferon-gamma (IFN-gamma), and tumor necrosis factor-alpha (TNF-alpha). We found that the concentrations of IL-10, IL-12, and IFN-gamma were significantly increased during the hangover state compared with the concentrations in normal conditions. These results support the suggestion that the dysregulated cytokine pathway (IL-10, IL-12, and IFN-gamma) is associated with the symptoms of hangovers.