Apolipoprotein E (APOE) has been identified as a major susceptibility marker for Alzheimer's disease (AD) and it has been proposed that a common polymorphism in the alpha1-antichymotrypsin (ACT) gene increases the risk of developing AD, when the combination of ACT/AA genotype and APOE epsilon4 allele segregate together. The ACT polymorphism was analysed in 218 sporadic late-onset AD patients and 101 healthy control subjects from Eastern Finland. Samples of the ACT polymorphism were divided into three subgroups according to their APOE genotypes and the genotyping of samples was done using the polymerase chain reaction (PCR) method. Any association between the AD group and the controls was tested with the chi2 test. Our data failed to detect any effect of polymorphism in the ACT genotypes associated with the APOE alleles, suggesting that in this population ACT does not increase the risk of AD.