Chronic alcohol use has profound modulatory effects on the immune system. Both the innate and the acquired immunity are compromised. The use of pharmacotherapy is increasingly applied to enhance the percentage of success in maintaining alcoholic patients in remission. Disulfiram, naltrexone and gamma hydroxybutiric acid are the drugs used for this purpose in Italian Addiction Services. In this study we analyze the effect of pharmacotherapy of alcohol dependence on immune responses in alcoholics. Six groups were studied. Group A included 10 patients who were still using alcohol. Group B consisted of 10 patients abstinent from alcohol in treatment only with group therapy. Groups C, D and E were composed of 10 patients each, treated for at least 6 months with oral doses of gamma hydroxybutiric acid, naltrexone or disulfiram respectively. Ten age- and sex-matched healthy volunteers who never misused alcohol were included as a control group. Lymphoproliferation and peripheral mononuclear cell production of the Th1 cytokines IL-2 and IFN-gamma, the Th2 cytokine IL-4, and of the pro-inflammatory cytokines IL-1 and TNF-alpha were evaluated in all the patients and controls. The level of activity of the hypothalamus pituitary adrenal axis was assessed. Both ACTH and cortisol levels in plasma were elevated in alcoholic patients with no treatment. In this group a significant alteration of cytokine production was observed. TNF and IFN-gamma were lower than controls, while the Th2 cytokine IL-4 was increased. These altered levels state for a Th1/Th2 unbalance characterized by decreased Th1 response in the presence of Th2 predominance. In patients undergoing pharmacological treatment, none of the immune parameters were different from those observed in healthy controls, independently of the type of drug administered. These data indicate that pharmacotherapy more than group therapy treatment is able to ameliorate the immune system functioning in alcoholic patients.