Serum total cholesterol (T-CHO), triglyceride (TG), high density lipoprotein cholesterol (HDL-C) and apolipoproteins (apo A-I, A-II, B, C-II, C-III and E) values were determined in 143 Japanese subjects undergoing coronary angiography. Among the factors measured, T-CHO, TG, apo B and C-III levels were significantly higher in patients with coronary artery disease (CAD) than in those without CAD. The HDL-C/T-CHO ratio was also significantly lower in patients with CAD. Although no parameters show differences between the group without CAD and the group of single vessel disease, T-CHO and apo B were significantly higher in the groups with double and triple vessel disease, and TG and apo C-III were also higher in the group with triple vessel disease compared with the normal group. Furthermore, the HDL-C/T-CHO ratio was significantly lower in the double and triple vessel groups, and HDL-C was lower only in the triple vessel group. The results indicate that changes in these parameters suggest a high likelihood of multiple vessel disease, and that an increase in TG and apo C-III levels is also one of the important indicators for CAD even in Japanese patients.