Moderate alcohol consumption has shown to induce benefits on host specific (cell-mediated and humoral) immune system, but there is scarce literature regarding first-line immune responses. The aim of this study was to investigate differences in non-specific immunity after alcohol abstention and moderate beer consumption in healthy adults. After a 30 day-alcohol abstemious period, 57 healthy volunteers were submitted to a daily moderate consumption of beer (330 mL for women and 660 mL for men, respectively) during the following 30 days. White blood cell counts and phagocytic and oxidative burst activity were evaluated at three points: a) basal, b) abstemious, c) after moderate consumption of beer. Absolute values of leukocytes, neutrophils, lymphocytes and basophiles (x10(9)/L) increased significantly in women from point b to point c (6.34 +/- 1.26 vs. 7.27 +/- 1.97, 3.43 +/- 0.88 vs. 4.13 +/- 1.53, 2.14 +/- 0.50 vs. 2.38 +/- 0.63, and 0.05 +/- 0.02 vs. 0.06 +/- 0.03, respectively; p < 0.05) as well as basophils in men (0.05 +/- 0.03 vs. 0.06 +/- 0.03). A significant increase of oxidative burst capacity was also observed after the moderate consumption of beer in both women (33.90 +/- 19.00 vs. 48.86 +/- 21.83) and men (27.39 +/- 18.13 vs. 39.25 +/- 24.53). In healthy adults, after 30 days of moderate beer consumption the parameter describing the non-specific immunity improved when compared to the basal situation. For several of these parameters, the response is more enhanced in women.