We report three cases of fusariosis that occurred during the treatment of acute leukemia, during the past 5 years at our institution. Case 1: A 70-year-old male with relapsed and refractory acute lymphoblastic leukemia (ALL) developed fever and multiple nodular lesions in both the lungs. Blood culture that was subsequently obtained revealed Fusarium species. Treatment with liposomal-amphotericin B (L-AMB) was ineffective, and the condition of the patient deteriorated rapidly leading to death. Case 2: A 28-year-old male with T-ALL developed echthyma gangrenosum (EG) ulcers on the scrotum during conditioning for transplantation. Antifungal therapy with L-AMB was ineffective, and later, itraconazole and micafungin (MCFG) were introduced. However, the engraftment was not achieved, and the patient died on day 27. Microbiological examination of EG samples collected on day 13 revealed infection by Fusarium species post mortem. Case 3: A 50-year-old male with blast crisis of chronic myeloid leukemia developed EG primarily on the trunk during chemotherapy. The patient died without any response to L-AMB and MCFG. A culture obtained from EG on day 19 yielded Fusarium species, post mortem. The prognosis of fusariosis is extremely poor. However, skin lesions such as EG may assist in the early diagnosis of the disseminated disease.