Nutritional support is one of the therapeutic modalities in the intensive care unit (ICU). Recently enteral feeding is recommended to start as soon as possible especially within 24 or 48 hours after admission. However, parenteral nutrition is important methods for nutritional support in patients who contraindicated for enteral feeding. During nutritional support, complications may occur regardless of methods. In parenteral nutrition, catheter related or metabolic complications are developed. Sometimes serious complications can occur. So, we have to understand the associated complications and try to prevent and detect earlier to manage them. (SMN 2013;4:1-5)