A general transcription factor IID (TFIID) binds to the TATA box promoter element and regulates the expression of most eukaryotic genes transcribed by RNA polymerase II (Pol II). A highly sensitive, specific and quantitative assay for human TFIID (hTFIID) mRNA was developed based on polymerase chain reaction (PCR). The distinctive points of our procedure include the use of small amount of total cellular RNA (1μg), a random primer for cDNA synthesis, β2-microglobulin (β2M) as an internal control and calculation of the relative value of hTFIID transcript from 32P-incorporation of the co-amplified PCR at different cycles. By this procedure, distribution of the hTFIID gene expression was for the first time demonstrated in normal human tissues and the amount of hTFIID mRNA was measured. In some tissues such as liver, fetal lung and placenta, moderate levels of hTFIID mRNA were detected. hTFIID transcript appeared correlated to total mRNA initiation and protein synthesis in tissue. This quantitative PCR procedure can be applied to more extensive studies of gene expression.