Many Actinomyces species are part of the oral microflora of humans. Actinomyces odontolyticus - associated infections are exceptionally rare, presenting an endogenous infection originating from mucous membranes. Immunodeficiency is often complicated by severe opportunistic bacterial infections leading to critical condition of the patient. We report a case of an immunosuppressed patient with fever and Actinomyces odontolyticus bacteremia. The patient poorly responded to the applied antimicrobial therapy and did not recover.