An experiment was conducted to assess the effects of different sources of fats added with an external emulsifier (lecithin) on the performances of Khaki Campbell Ducks in an eight-week trial. Ducks were grouped into five dietary groups with three replicates (n = 10) in each group. The ducks were fed with a basal diet supplemented with 3% soybean oil and without emulsifier (C1), 3% palm oil without emulsifier (C2), 3% soybean oil with emulsifier (T1), 3% palm oil with emulsifier (T2) and 3% lard with emulsifier (T3). The growth performance of ducks did not vary (P > 0.1) among the dietary treatments. Feed intakes by ducks were also similar (P > 0.1) among treatments within the periods. Similarly, feed intake to gain ratios were not affected by any dietary treatments. The metabolizability of dry matter, crude protein and nitrogen free extract also did not change (P > 0.1) due to various dietary treatments. However, the metabolizability of fats in all the emulsifier added groups (T1, T2 and T3) was greater (P < 0.05) than the dietary groups without emulsifier (C1 and C2). Various carcass traits such as percentages of hot carcass, breast, legs, lungs, hearts, gizzard, giblets weights relative to bodyweights did not vary (P > 0.1) among the groups. The carcass yield tended (P = 0.06) to be greater in the T1 than in the C1 group. The moisture, fats, protein and ash composition of meat (percent on fresh basis) was similar (P > 0.1) among treatments. In conclusion, supplementation of lecithin as an emulsifier to the diets containing different sources of fats (3%) appears to have no major impact on the overall performances of Khaki Campbell ducks in their grower phase.