Adverse effects of ethyl alcohol (EtOH), the most abused substance, on the immune system are not fully understood. We hypothesized that Jurkat T‐lymphocytes (JTL) cell counts will decrease in the presence of alcohol, and that after 48h growing in increasing EtOH concentrations (0.001%‐50% v/v) would result in a simple dose‐response curve with defined IC50 for EtOH.The Countess automated cell counter was used to measure the number of JTL in the Trypan Blue exclusive manner. The dose‐response relationship for EtOH alone obtained was far from the expected sigmoidal or biphasic shape. First, cell count was significantly increased at 0.01% EtOH compared to control. Second, cell count remained the same at 5%, 10%, and 20% EtOH with no proliferation. This complex shape of the dose response curve indicates potential multiple effects of EtOH on JTL with possibly different mechanisms. To define the components of the dose‐response, further studies will be performed and more data points obtained to allow curve fitting. Live cells were also found at 30% EtOH but were uncountable by the Countess's image analysis because the media turned cloudy at this and higher EtOH concentrations. No live cells were detected at 50% EtOH.The EGCG concentration that can be achieved in plasma by drinking green tea is 10 μM. When 10 μM of EGCG was added 5 min before EtOH treatment, it abrogated the effects of 0.01% EtOH and shifted the IC50 for EtOH from 3% to 10%. At this point we conclude that protective effects of EGCG may be due to potential interactions with one or more pathways by which EtOH acts on Jurkat T‐cells.