We assessed the association of four polymorphisms (promoter P3 -681C>G, P2 -689C>T, Pro12Ala, and 1431C>T) in peroxisome proliferator-activated receptor gamma (PPARgamma) with the metabolic syndrome risk in a large, French population study (n = 1,155). In this sample, 279 men and women presented with metabolic syndrome according to the National Cholesterol Education Program Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (Adult Treatment Panel III) criteria. When taken individually, none of the polymorphisms was significantly associated with the metabolic syndrome. Haplotype analyses, in contrast, revealed a significant enrichment of the GTGC haplotype frequency (corresponding to the P3 -681C>G, P2 -689C>T, Pro12Ala (C/G), and 1431C>T polymorphisms in this order) among those with metabolic syndrome compared with control subjects. Compared with the most common CCCC haplotype, the adjusted odds ratio (OR) (95% CI) of the metabolic syndrome for bearers of the GTGC haplotype was 2.37 (1.42-3.95; P = 0.002), 1.92 (1.00-3.72; P = 0.05), and 2.47 (1.09-5.62; P = 0.045) in the whole sample of men and women, respectively. Similar results were obtained when using another haplotype (GCCC, GTGT, CCCT, or GCCT) as a reference. Furthermore, when the GTGC haplotype frequency was tested alone (i.e., versus the frequency of the five other haplotypes together), the OR (95% CI) of the metabolic syndrome was 2.30 (1.05-5.00; P = 0.022). These data show that only the frequency of the GTGC haplotype was different between subjects with and without metabolic syndrome. Further analyses stratified on the 1431C>T single nucleotide polymorphism (SNP) indicated that the rare alleles of the P2 -689C>T and Pro12Ala SNPs were associated with an increased risk of the metabolic syndrome when combined to the 1431CC genotype. In conclusion, a specific haplotype of PPARgamma polymorphisms is associated with an increased risk of the metabolic syndrome in a French general population.