Alternate intravenously administered infusions in 127 surgical patients had 500 ml of clinical dextran 75 added per day. The degree of phlebitis at the site of infusion was evaluated at the time of its discontinuation. The incidence of infusion phlebitis was found to be 30% in both treated and control groups, volume and duration of infusion being comparable. These results are discussed in relation to the value of dextran in the prevention and treatment of thrombophlebitis.