Deep, respiratory tract and ear infections due to Microascaceae (Pseudallescheria, Scedosporium, Microascus or Scopulariopsis) were studied nationwide in Finland during 1993-2002. The data were based on 52,000 fungal cultures that represented about 50% of all such specimens in Finland and included all Finnish cases of profound immunosuppression. There were 39 cases that were re-evaluated as clinically significant, i.e., three pneumonias, two deep pedal infections and five wound infections, 11 sinusitis and 18 ear infections. The pedal infections and most pneumonias occurred in immunocompromised patients. Most cases, except the ear infections, were due to Pseudallescheria boydii. Two patients had lethal P. boydii pneumonia and a deep P. boydii infection of the foot contributed to a third lethal case. Two of the patients with lethal outcomes had received an allogeneic haematopoietic stem cell transplantation (AHSCT). Two patients with haematological malignancies were cured of deep site infections by a prolonged course of itraconazole. Wound, sinus and ear infections were cured or improved by local surgery or topical therapy. There were 0.8-1.7 cases of any type of infection per million inhabitants per year (MY) and 3.4 cases/1000 AHSCT. Mortality associated with Microascaceae in any type of patient was 0.06-0.12 MY.