Cholecystokinin (CCK) is the most widely distributed neuropeptide in the central nervous system. One of its several functions is to modulate the release of dopamine in brain areas involved in reinforcement and reward behavior. The aim of this study was to investigate the association of CCK system genes (CCK, CCK(A) and CCK(B) receptor genes) with alcohol dependence using single nucleotide polymorphisms (SNPs) as genetic markers. A total of 257 psychiatrically interviewed Finns were genotyped for CCK (-45C>T), CCK(A) (Val365Ile) and CCK(B) (Val125Ile) receptor polymorphisms. Allele frequencies were compared between 150 unrelated healthy Finnish controls and 107 unrelated alcohol-dependent subjects (DSM-III-R criteria), who were also criminal offenders. The frequency of the CCK -45T allele was not significantly different between controls [0.07] and alcoholics [0.09]. The CCK(B) receptor polymorphism Val125Ile was also not associated with alcoholism and the Ile125 allele frequencies were 0.05 in controls vs. 0.06 in alcohol-dependent subjects. A CCK(A) receptor marker, Val365Ile, was uninformative in this Finnish dataset; all subjects were Val365/Val365 homozygous. The results suggest that CCK -45C>T and CCKBR Val125Ile polymorphisms do not have a major role in alcohol dependence in the population studied. The role of the CCK(A) the receptor in alcohol dependence remains open until additional DNA sequence variants for this gene become available.