Naive adult male Wistar rats free to choose between water or 10% ethanol (v/v) spontaneously became water-preferring (WP) rats, as they drank mainly water (approximately 35 ml per day), or alcohol-drinking (ED) rats, as they also drank a significant amount of ethanol (approximately 14 ml per day). The selective CCK A receptor antagonist L-364,718 at doses selective for the CCK A receptor (5 μg/kg, IP) halved the consumption of alcohol of the ED rats without modifiying their total liquid intake. In contrast, the CCK B antagonists L-365,260 or GV150013 were without effect when used at doses selective for the CCK B receptor. These data indicate that the CCK system could be involved in the modulation of alcohol intake. In particular, they suggest that CCK A receptors could play a role in the ethanol preference.