The echinocandins provide an attractive new option for prophylactic and empirical treatment of invasive fungal infections in patients with neutropenia after intensive cytotoxic chemotherapy or hematopoietic stem cell transplantation. We present two patients with hematological diseases who experienced massive intravascular hemolysis followed by renal failure after administration of micafungin. In indirect antiglobulin test, significant agglutination was observed when red blood cells were exposed to the mixture of micafungin and either of the patients' plasma samples, indicating that production of antibodies directed against both micafungin and red blood cell membrane induced hemolysis attack. Micafungin-mediated immune hemolysis represents an uncommon but life-threatening adverse reaction leading to renal failure.