Oerskovia turbata is a yellow, motile actinomycete, which before now has only been found in soil and has not been known to cause disease in man or animals. It was isolated from 29 cultures of blood taken during 6 months from an urban pensioner after homograft replacement of his aortic valve. The combination of ampicillin, sulfamethoxazole, and trimethoprim was lethal for O. turbata in vitro; however, antimicrobial therapy alone failed to eradicate the patient's infection. Cure was achieved after the infected homograft was replaced with a prosthetic aortic valve. Although the source of O. turbata in this patient is unknown, sterilization of homograft valves with antimicrobial solutions is difficult. Moreover, environmental contamination during cardiopulmonary bypass is common. Oerskovia turbata is another opportunistic pathogen of man.