The earthquake that struck the Hanshin-Awaji district on January 17, 1995, was one of the most destructive to occur in Japan. We analyzed the changes in microorganisms isolated from patients with hematological disorders in relation to this earthquake. We reviewed a total of 4137 microbial cultures obtained over 1-year periods before and after the earthquake. There were 123 neutropenic patients admitted during the study period (54 before the earthquake and 69 afterwards). No significant differences in clinical characteristics and underlying diseases were found between the 2 groups. Polynomial analysis revealed a significant increase in the isolation of Candida albicans, Candida glabrata, and Pseudomonas aeruginosa from sputum and stool cultures after the earthquake. These microorganisms increased markedly in patients from severe earthquake-damaged areas. In neutropenic patients with hematological disorders, microbial isolates changed significantly after the Hanshin-Awaji earthquake. These changes may have been related to physical and emotional stress, as well as to the deterioration of environmental factors such as food, air, and water.