Lipid metabolism in marasmus has been poorly studied compared with that in kwashiorkor. Published studies show normal or high plasma triglycerides and low cholesterol concentrations. We studied some plasma lipid indexes, including total, HDL, and LDL cholesterol; triglycerides; apolipoproteins A-I, A-II, B, C-III, and E; and lipoprotein particles containing apo A-I, apo A-I and A-II (Lp A-I:A-II) Lp C-III:B, and Lp E:B in Mauritanian marasmic children compared with a control group. We found in patients low total, HDL, and LDL cholesterol and normal Lp A-I concentrations, which suggest that the cholesterol reverse transport system is not altered. We observed normal triglyceride concentrations and significantly increased Lp C-III:B and Lp E:B, which are triglyceride-rich particles. These data suggest that the marasmic state led to quantitative and structural modifications of the triglyceride-rich lipoproteins, defined by their apolipoprotein composition, and was probably related to undercatabolism.