With the aim of identifying putative quantitative trait loci (QTLs) involved in the regulation of blood pressure, we have carried out association studies at a candidate genetic locus-a human pancreatic phospholipase A2 (PLA2) gene localized on chromosome 12. Positive associations were found between the presence of a Taq I dimorphic site localized in the first intron of this gene and hypertension in three sample populations (two from USA and one from Germany). These results indicate that a QTL implicated in determining an individual's genetic susceptibility to hypertension could be present within up to 30 cM of this human PLA2 gene.