Patterns of hypocholesterolemic lipid fractions in 295 patients with liver diseases, malignant tumors, arteriosclerotic and renal diseases with cholesterol (Chol) levels of <30 mg/dl were classified using a simultaneous analytical method for the Chol and triglyceride (TG) fractions (Chol/Trig Combo System). Hypocholesterolemia was classified as follows: IV, Type IV on WHO hyperlipidemia phenotype classification; intermediate density lipoprotein (IDL), cases with appearance of IDL, including appearance of Lp(a); high + low density lipoproteins (HDL+LDL), lipids mostly consisting of HDL and LDL fractions; HDL abnormality, cases with slow alphaHDL or fast HDL; abnormal LDL, both Chol and TG fractions mostly consisting of LDL fraction; normal type, ratios of HDL, very low density lipoproteins (VLD) and LDL fractions were almost normal; and low HDL, HDL-C was <30 mg/dl. Many patients with liver diseases had HDL+LDL (45%), and abnormal LDL was noted in 13% of the cases. In malignant tumors, the frequencies of low HDL, normal type, and HDL+LDL cases were similar (22-30%). In arteriosclerosis, normal type accounted for 46% of the cases, and the frequency of normal type was higher (60%) in renal diseases. Mortality rate (within 1 year after measurement) was then compared among lipid patterns. In liver diseases, mortality rate increased in the following order: abnormal LDL (55%); low HDL (31%); HDL abnormality (25%); and HDL+LDL (21%). No deaths were seen among patients with normal type. In malignant tumors, mortality rate was very high (88%) in patients with HDL+LDL, but low in patients with normal type (22%) and low HDL (9%). Mortality rate was low in patients with arteriosclerosis and renal diseases in the short-term follow-up period (1 year). In the comparisons of distribution, mean, and appearance rate of charge modification frequency (CMF) among lipid patterns, parameters were high in all patterns other than HDL+LDL. Classification of hypocholesterolemia lipid patterns and evaluation of CMF may therefore be clinically useful.