Idiopathic hypereosinophilic syndrome is characterized by prolonged markedly elevated peripheral blood eosinophil count and eosinophil-related tissue damage to variable organs without an identifiable underlying cause. Eosinophilopoiesis is related with T-lymphocyte activation and cytokine cascade controlling eosinophilic production. It shows tissue infiltration in many organs including endomyocardium, lung, liver, gastrointestinal tract. Here we report a case of idiopathic hypereosinophilic syndrome presenting ruptured rectus sheath hematoma due to coagulopathy involving the liver. Severe postoperative complications were developed after general anesthesia. The patient suffered from life-threatening acute respiratory distress syndrome (ARDS). This case suggest that, in patients with marked eosinophilia requiring general anesthesia, perioperative steroid cover is advisable. This may reduce or prevent serious lung damage and other complications.