A program to modify the prescribing of antilipemic agents by promoting the use of extended-release niacin tablets is described. Between December 1987 and August 1988, pharmacists at a 1188-bed Veterans Affairs medical center observed a large increase in the number of outpatient prescriptions for antilipemic agents. In an attempt to control costs, a program to promote the use of extended-release niacin tablets for treating hyperlipemia was conducted during August and September 1988. Various educational materials on niacin were distributed to physicians. A display on therapy of hyperlipemia was featured at the monthly drug fair, and articles on niacin were presented during a journal club meeting of ambulatory-care clinicians. Pharmacists succeeded in having extended-release niacin tablets placed on the formulary in September. Data on the number of prescriptions filled for antilipemic agents were collected before and after the niacin promotional program. The number of prescriptions filled for extended-release niacin 500-mg tablets increased steadily during a six-month study period after the program ended; the number of prescriptions filled for regular niacin decreased by 50%. As prescribing of extended-release niacin increased, prescribing of colestipol, gemfibrozil, and probucol declined. The promotional program was well received by most of the medical staff. A program of education and formulary management successfully changed physician prescribing habits for antilipemic agents.