Pigs of a high lean strain reared via an SEW scheme were self-fed a basal diet supplemented with 0, 15, or 30 mg niacin/kg diet from 10 to 27 kg body weight. The basal diet contained 18 mg of total niacin and 9.4 mg of bioavailable niacin per kg diet. Dietary niacin supplementation did not alter pig growth, efficiency of feed utilization, or body nutrient (protein, fat) accretion. Based on these results, dietary niacin needs of high lean, high health pigs are not greater than current NRC (1998) estimated requirements.