Introduction. Kasabach-Merritt phenomenon (KMP) is a rare condition associated with vascular tumors such as kaposiform hemangioendothelioma and tufted angioma; it can be life threatening, due to its consumptive coagulopathy. Thrombocytopenia and hypofibrinogenemia are characteristic of KMP, and anemia and raised d-dimer levels can also be detected. Here, we report a 7-month-old Cambodian with the condition. Case Presentation. The infant was admitted to the National Pediatric Hospital in Phnom Penh because of a mass on the right side of the neck that had been progressively enlarging. The patient had severe thrombocytopenia (8,000/µL), anemia (Hb 7.6g/dL) and reduced fibrinogen level (1.5g/L). CT scan and histology of the lesion confirmed a diagnosis of hemangioma. Kasabach-Merritt phenomenon was diagnosed, and the infant was treated with platelets and fresh frozen plasma infusions, prednisolone (2mg/kg/day) and propranolol (2.5mg/kg/day). After eight weeks of therapy, platelets raised to 102,000/µL. The infant developed Cushing’s syndrome after 6 months of treatment and prednisolone was scaled down to a maintenance dose of 0.5mg/kg/day. Fibrinogen levels went back to normal (2.14g/L) after seventeen months of treatment, and the tumor shrinked significantly. Conclusion. This case report shows that a combination of prednisolone and propranolol has been effective for KMP and kaposiform hemangioendothelioma. Timely recognition and treatment of Kasabach-Merritt phenomenon’s are essenti