We studied the effect of low-dose hydrocortisone and heparin added to peripheral intravenous fluid on episodes and severity of thrombophlebitis. Osmolal solutions of 860 mOsm/kg H2O with heparin and hydrocortisone (feed A) and without heparin and hydrocortisone (feed B) were infused into surgical and ear, nose, and throat patients for peripheral intravenous nutrition. The addition of heparin (500 U/L) and hydrocortisone (10 mg/L) in 10% dextrose in half-strength normal saline and 500 ml 5% crystalline amino acid solution infused simultaneously via a Y line significantly reduced the episodes and severity of thrombophlebitis. Thus, the administration of low-dose hydrocortisone and heparin with peripheral fluids is beneficial in preventing thrombophlebitis.