High-performance thin layer chromatography (HPTLC) was used to determine neutral lipids in the cecal contents and mucosa of domestic chicks and ICR mice, and in the cecal mucosa of chicks infected withZygocotyle lunata(Trematoda). Silica gel plates were developed with petroleum ether-diethyl ether-acetic acid (80:20:1) mobile phase, and neutral lipids were detected using phosphomolybdic acid reagent. The cholesteryl ester fraction was quantified by HPTLC-densitometry. HPTLC analysis showed differences in the neutral lipid composition of the cecal contents of chicks, compared with the cecal contents of ICR mice. There were differences in neutral lipid profiles between the uninfected cecal mucosa of chicks and chick cecal mucosa infected withZ lunata. These findings showed that this parasite can alter the neutral lipid composition of the host cecal mucosa.