Although previous invasive fungal diseases (IFD) pose a significant risk of reactivation during successive chemotherapies in patients with acute leukemia, and secondary antifungal prophylaxis is regarded as mandatory, much remains unknown about the optimal strategy including the efficacy of voriconazole. During January 2006 and October 2008, a total of 15 patients with acute leukemia had pulmonary IFD (4 probable and 11 possible cases) before or during chemotherapy. After successful treatment of primary IFD with oral voriconazole, all of them received voriconazole during a total of 35 courses of successive chemotherapy. All but one patient successfully accomplished planned treatment without suspected IFD or significant toxicity despite profound neutropenia. We retrieved the previous reports of myelosuppressive therapies after IFD using various secondary prophylaxes, and showed that voriconazole is the most effective drug to suppress IFD relapses.