We compared the usefulness of a polymerase chain reaction (PCR) assay for the early diagnosis of invasive pulmonary aspergillosis with the serodiagnosis of sufficient concentrations of galactomannan using the same serum samples. A patient was treated with prednisolone for the management of hepatitis. Computed tomography (CT) scan of the chest showed the nodular shadow with a cavity containing a clear fungus ball. DNA of Aspergillus spp. from a serum sample was detected and using the same serum sample, both latex agglutination and sandwich enzyme-linked immunosorbent assay (ELISA) of galactomannan were negative. PCR assay provides an early diagnosis of invasive pulmonary aspergillosis compared with ELISA of galactomannan.