Four barrows of approximately 40 kg initial body weight, fitted with post-valvular T-cecum cannulas, were used to study the effect of lecithin as an external emulsifier on apparent ileal and overall digestibility of crude fat, fatty acids, and other dietary nutrients (DM, N, GE, crude fiber [CF], P, Ca, and Mg), as well as the utilization of N, GE, Ca, P, and Mg. Two levels of lecithin (0 and .24%) and two levels of rendered fat (0 and 6%) in cereal-soybean meal-based diets were investigated according to a 4 x 4 Latin square design. No significant interactions were found between lecithin and rendered fat for apparent digestibility of crude fat as estimated at the end of the small intestine and the total digestive tract. Lecithin decreased the apparent ileal digestibility of C16:0 fatty acid (P < .1) and the apparent overall digestibility of C14:0 fatty acid (P < .05) and C18:2 fatty acid (P < .1). The apparent ileal and overall digestibility of crude fat (P < .001) and total fatty acids (P < .05) increased with the inclusion of rendered fat in diets. Furthermore, rendered fat increased the apparent ileal and overall digestibility of C14:0 (P < .01), C16:1 (ileal, P < .001; overall, P < .1), and C18:1 (P < .05) fatty acids and the apparent overall digestibility of C18:0 (P < .001) fatty acid. Lecithin had no impact on the apparent digestibility and retention (percentage of intake) of GE, N, total P, Ca, and Mg.(ABSTRACT TRUNCATED AT 250 WORDS)