Bripiodionen (1), a new natural product, was isolated from Streptomyces sp. WC76599 during the screening of microbial fermentation extracts for their ability to inhibit human cytomegalovirus protease. The structure of 1 was elucidated by spectroscopic methods. Compound 1 displayed inhibitory activity against human cytomegalovirus protease with an IC50 value of 30 microM.