To test the hypothesis that the A/T polymorphism of the fatty acid-binding protein 2 gene (FABP2) is associated with impaired lipid metabolism and cardiovascular disease, we compared clinical characteristics and a parental history of cardiovascular disease between 213 sibling pairs discordant for the polymorphism. Siblings with an excess of the T54 allele had higher triglyceride (P = 0.002) and cholesterol (P = 0.019) concentrations than siblings with the A54 allele. Parents of offspring with the T54T and T54A genotypes reported an increased prevalence of stroke compared to parents of offspring with the A54A genotype (P = 0.007). In summary, we have confirmed the association of the FABP2 T54 allele with increased concentrations of cholesterol and triglycerides in genotype-discordant sibling pairs. We also present novel evidence that genetic variation in the FABP2 gene may increase susceptibility to stroke.