The incidence of phlebitis was determined for heparin-lock needles after use of three different methods of skin preparation and follow-up care. Phlebitis was significantly more frequent when iodophor solution and iodophor ointment, respectively, were used than when iodophor solution alone was used for heparin-lock needles in use longer than 48 hours, with more than ten manipulations of the systems, and when only one drug was infused through the systems. Iodophor solution skin preparation followed by daily application of iodophor solution is recommended to minimize the occurrence of associated phlebitis. © 1979, American Medical Association. All rights reserved.