The purpose of this study was to identify and quantify neutral lipids in the urine and feces of mice experimentally infected with Schistosoma mansoni. Four infected and three control mice were used in this study. The samples were collected weekly for eight weeks. Samples from the infected mice were compared to those from the uninfected ones. The analyzed lipids in both feces and urine samples were free sterols, free fatty acids, triacylglycerols, and methyl esters. Steryl esters were also analyzed in fecal samples. The neutral lipids were separated on channeled preadsorbant Analtech HPTLC-HLF 20 x 10-cm silica gel plates with petroleum ether-diethyl ether-glacial acetic acid (80:20:1) mobile phase and detected with 5% ethanolic phosphomolybdic acid spray reagent. Quantification was carried out by use of a CAMAG Scanner 3 in the visible mode. Significant differences between infected and uninfected samples were found in methyl esters of feces after four weeks, and steryl esters of feces after five weeks. Also, triacylglycerols in urine samples were statistically different at eight weeks in infected versus uninfected samples. The results of our study suggest that certain neutral lipids in the urine and feces of mice may serve as indicators of infection with S. mansoni.