One of the most common causes of phlebitis in hospitalized patients is intravenous catheters. The material of the catheter is a determining factor in the development of phlebitis, as are factors such as age, gender, and medical diagnosis of the patient. The aim of this study, conducted in the coronary care unit of a 384-bed hospital in Ankara, Turkey, was to determine the effect of two different short peripheral catheters on phlebitis development caused by i.v. treatment. Overall, 255 patients constituted the study sample (130 with Teflon, 125 with Vialon catheters). Both groups were followed up for phlebitis development for 6 days. The total phlebitis rate was 36.8%, with almost half of the patients (49.2%) in the Teflon catheter group and 24.0% of patients in the Vialon catheter group. A significant statistical relationship was found between phlebitis rate and variables such as gender, catheter material, and indwelling time. The results of the study demonstrate that Vialon catheters are associated with less risk of catheter-induced phlebitis than are Teflon catheters.