The recent development of real-time PCR allows for the rapid and accurate quantitation of gene expression in cells and tissues. Real-time PCR instrumentation is designed for the simultaneous quantitation of gene expression from a few samples up to 384 samples. The normal tissue expression profile of a gene can provide useful insights into its potential role in normal physiological processes. When combined with the tissue expression profile of the gene in diseased tissues, information concerning the potential role in pathological processes can be determined. This unit describes a protocol to determine the relative abundance of mRNA in a panel of human tissues using real-time PCR.