AbstractObjectives: To describe the genomic expression profile or transcriptome of adipose tissue using the serial analysis of gene expression method.Research Methods and Procedures: The serial analysis of gene expression strategy is based on isolation of short sequences (tags), which usually correspond to unique transcripts, and on their concatenation into long DNA molecules, which are then cloned and sequenced. Experiments were performed with mRNA from retroperitoneal adipose tissue of male C57BL6 mice.Results: We isolated 45, 996 tags corresponding to more than 17, 000 different genes. Eighty‐eight genes were expressed at more than 0.1% of the total population and represented 26% of the mRNA population identified. The most expressed genes were: carbonic anhydrase 3 (1.97%), cytochrome c oxidase (COX) 1 (1.47%), COX2 (1.25%), diazepam binding inhibitor (1.04%), a novel transcript (0.87%), COX3 (0.55%), fatty acid‐binding protein 4 (0.55%), and NADH dehydrogenase 4 (0.52%). Other genes known to be expressed in adipose tissue, such as uncoupling protein 2, angiotensinogen, adipsin, and insulin‐like growth factor 1, were found at a lower level. Several tags corresponding to novel transcripts were also found.Discussion: To our knowledge, the present results provide for the first time a quantitative description of the transcriptome in adipose tissue.