Abstract The use of alcohol for consumption and other purposes is widely prevalent in our society. High concentration of alcohol (ethanol) in the household and clinical cleaners is employed for disinfecting. Deleterious effects of alcohol abuse in terms of death and dysfunction of cells, including immune-cells, has been extensively documented. However, moderate consumption of alcoholic beverages has been indicated to be beneficial. In this study, we sought to investigate the effects of sub-lethal doses of alcohol on the interaction of innate and adaptive immunity. We used murine bone marrow-derived macrophages (BMM) as antigen presenting cells and naïve T-cells isolated from spleens of C57BL/6 mice for in vitro T-helper differentiation assays. We found that doses of alcohol at 3% (v/v) or higher induces severe cell death, whereas lower concentrations of alcohol (<2% v/v) modulates the BMM activity for increased differentiation of T-regulatory cells (Tregs), which play a major role in preventing inflammation. Further, alcohol at lower doses also reversed the inhibitory effect of the endotoxin lipopolysaccharide (LPS) on Treg differentiation. Interestingly, BMM treated with alcohol also increased differentiation of TH17 cells. We also investigated the effects of alcohol-treated BMM on immune-modulation of T-helper differentiation in vivo. The data provide insights for immunomodulatory effects of low doses of alcohol and have implications for the regulation of Tregs.