The genetic association of interleukin-1 (IL-1) with periodontitis has been investigated in different populations. Failure to detect an association with IL-1 genotypes in European Caucasians with aggressive periodontitis (AGP) has recently been reported. No data from Central American Hispanics are available. The purpose of this explorative study was to study the association between IL-1 genotypes and AGP in two populations. Ninety-one subjects, 28 North European patients and 33 controls together with 16 Central American patients and 14 controls were included in the study according to validated radiographic and clinical criteria. Two polymorphisms, IL-1alpha G(+4845)-T and IL-1beta C(+3954)-T were analysed by means of polymerase chain reaction-restriction fragment length polymorphism. The association between presence of specific genotypes and disease status was estimated by the odds ratio. A logistic regression was also used in order to investigate whether the occurrence of the disease depends upon the combination of the IL-1A and IL-1B alleles in the population. A similar distribution of genotypes between patients and controls in both populations was detected. The frequency of allele 1 of the IL-1A gene was higher in patients of both populations compared with controls, however, no statistical significant differences were found between patients and controls.