Pseudallescheria boydii, a common soil organism, is best known as the causative agent of mycetoma. Isolation of the organism from sites other than the extremities is relatively uncommon. However, the use of corticosteroids and cancer chemotherapy has been associated with an increasing frequency of localized superinfection as well as disseminated disease. Recently, an increased number of disseminated P boydii infections, primarily associated with immunosuppressed patients, has been reported in the literature. We diagnosed an additional case of P boydii in a 16-year-old boy who had acute lymphoblastic leukemia and manifested a disseminated infection during reinduction chemotherapy. The unusual features of this case were the extent of organ involvement, which was more wide-spread than previously noted in the literature, and the presence of conidia in sections of an endocardial thrombus.