Many patients have been suffered from Hand-Foot-Mouth Disease (HFMD) in the North of Vietnam since August 2011. Some cases had severe complication, leading to death because of neurological damage, circulatory and respiratory failure. IV ImunoGlobulin (IVIG) is necessary for severe cases. The study was to describe clinical features and laboratory findings and to preliminarily assess the results of IVIG in National hospital of Pediatrics. From 1/8/2011 to 30/11/2011, 44/460 patients with severe HFMD were received IVIG in National hospital of Paediatrics. The first symptom was high fever (97.7 percent ), erythematous maculopapular rash on the hands an the feet (88.7 percent) and vomiting (11.4 percent). Most of them were under 3 years old. Complications appeared 2-5 days after onset of the disease, with tachycard and startle reflex (63.6 percent) and the laboratory were hyperleucocyte and hyperplatelet. IVIG improved outcome of the disease. Severe HFMD often occurs in patients under 3 years old with high fever, startle reflex tachycardia and vomiting. IVIG improved outcome of the disease. However, clinical trials are needed to confirm the evidence.