In order to evaluate the clinical significance of Aspergillus-positive culture results from the lower respiratory tract specimens of elderly hospitalized patients, and to identify the clinical variables that differentiate between colonization and infection with Aspergillus spp. in this patient population, a retrospective study was conducted. The records of 66 elderly patients whose lower respiratory tract specimens yielded Aspergillus spp. between January 1995 and July 2000 were examined. The majority of the patients ( n=61) were determined to be colonized with Aspergillus spp., and serious lung infection due to Aspergillus spp. was rare. Clinical, radiological, and microbiological data did not help differentiate between infection and colonization.