We determined the chromosomal localization and partial genomic structure of the coding region of the human PPARγ gene (hPPARγ), a nuclear receptor important for adipocyte differentiation and function. Sequence analysis and long PCR of human genomic DNA with primers that span putative introns revealed that intron positions and sizes of hPPARγ are similar to those previously determined for the mouse PPARγ gene[13]. Fluorescent in situ hybridization localized hPPARγ to chromosome 3, band 3p25. Radiation hybrid mapping with two independent primer pairs was consistent with hPPARγ being within 1.5 Mb of marker D3S1263 on 3p25-p24.2. These sequences of the intron/exon junctions of the 6 coding exons shared by hPPARγ1 and hPPARγ 2 will facilitate screening for possible mutations. Furthermore, D3S1263 is a suitable polymorphic marker for linkage analysis to evaluate PPARγ's potential contribution to genetic susceptibility to obesity, lipoatrophy, insulin resistance, and diabetes.