Male Wistar rats were able to drink water and different percentages of ethyl alcohol in a free-choice paradigm. Our results showed a clear-cut preference for 2 and 3% ethanol concentration. Addition of quinine in both drinking bottles increased preference for alcohol, while dilution of saccharin in both bottles totally suppressed this preference for the alcohol bottle. In this alcohol-water choice procedure, naloxone decreased the amount of alcohol intake without altering the amount drunk from the water bottle. This decrease was independent of the palatable or nonpalatable substances added to alcohol and also independent of the percentage of alcohol. Interpretation was done in terms of action of naloxone on the rewarding property of alcohol, or in terms of satiety mechanism for alcohol regulated by naloxone.