The aim of this review is to present and discuss the effect of different levels of alcohol consumption on the immune system. Not only the amount consumed but also the type of alcoholic beverage have to be taken into account in order to determine the consequences on activity, number, distribution, balance, interaction and response of immunocompetent cells. The association between alcohol exposure and the risk of developing an alcohol-related disease is multifactorial. In fact, age, gender, smoking habits, dietary intake and exercise are involved among other factors. The evaluation of the host cellular and humoral immune responses has shown that alcohol may induce some benefits when consumption is moderate. Moreover, those alcoholic beverages that contain antioxidants, such as red wine, could be protectors against immune cell damage. According to the literature consulted, the daily consumption of 10-12 g and 20-24 g of alcohol for women and men, respectively, is considered to be a moderate intake; the type of beverage has been established not to be important when defining moderation. Particular attention is often focused on the U- or J-shaped curve which also suggests that light to moderate drinking produces a protective effect. Such an inverse relationship indicates a reduction of risk for both light and moderate consumers and a higher risk not only for hard drinkers, but also for non-consumers.