One hundred and sixty seven Japanese cases of sudden cardiac death and 78 cases of control death underwent autopsy within 12 h after death were studied. Heart weight was 9.2 % higher in SCD cases than controls (P < 0.05). Moreover 57.5 % or 96/167 of the cases had more than grade (2+) coronary atherosclerosis versus 21.8 % or 17 of 78 controls (P < 0.01). Approximately 2/3 of the cases had full stomach, reflecting the postprandial state at the time of death. Plasma TC, TG, VLDL-C, LDL-C were significantly elevated (P < 0.001) together with RLP-C (P < 0.01), RLP-TG (P < 0.005) in SCD cases. Plasma RLP-apoB-100 levels were significantly elevated in SCD (P < −0.001), but apoB-48 levels were not. The median ratio of apoB-100/apoB-48 in RLP was 7.1 in SCD. The median RLP-TG/RLP-C ratio was 4.7, which suggested a large VLDL size. When apoB-48 and apoB-100 in RLP were divided into two groups, above and below the median level, respectively, apoB-48 inversely correlated with RLP-C (P < 0.05) and RLP-TG (P < 0.01), while apoB-100 in RLP positively correlated with RLP-C (P < 0.01) in SCD cases. In conclusion, these results indicated that apoB-100 carrying lipoproteins, not apoB-48 carrying lipoproteins, were the major subset of RLP associated with sudden cardiac death in the postprandial state, regardless to the severity of coronary atherosclerosis.