Rat and human steroidogenic organs contain an enzyme activity that is indistinguishable from hepatic lipase present in liver. Using primers that recognize exons 5 and 8 of the rat and human HL gene, a 596-bp product was found by RT-PCR in rat liver, adrenal, ovaries and testes, but not in heart and kidney. A similar product was also observed with human hyperplastic adrenocortical tissue. Identity of this product with part of the HL cDNA was confirmed by restriction mapping and internal re-amplification. Our results indicate that the HL gene is transcribed in steroidogenic tissues that also contain HL protein.