Five groups of 10 single comb white leghorn hens were fed different diets (standard corn/soy laying rations supplemented with edible oils) to ascertain the effect of trans-fat deposition in eggs. Trans-fat contents of the feeds and eggs were determined by gas chromatography (GC) and Fourier transform infrared (FTIR) spectroscopy. Diets devoid of hydrogenated oils contained no detectable levels of trans-fats. Feeds supplemented with tallow, shortening, or their combination contained 2.780.08, 3.250.03, and 2.850.05 g/100-g dietary fat, and 3.330.32, 4.160.03, and 3.520.05 g/100-g dietary fat as assessed by GC and FTIR, respectively. Eggs from hens fed these latter diets contained 0.680.05, 0.810.05, and 0.760.04 g/100 g dietary fat, by GC, but were below the 1% detection limit of FTIR. Nearly 25% of trans-fats in the diets accumulated in the eggs. Supplementation of edible oils did not appreciably increase trans-fat levels in the eggs. Data acquired by these methods correlated well, r=0.98.