Atherosclerotic cardiovascular disease (ASCVD) is the most frequent cause of death across the world, and thus we need to keep finding out factors associated with this important outcome1. In addition, the number of patients with heart failure (HF) and atrial fibrillation (AF) has been increasing with our aging societies2, 3, 4, 5, 6, 7. Although there are some new medications that can reduce the risk for HF8,9, and now we have useful anti-coagulant therapies10 and more advanced catheter ablation technique for AF11, we need to keep finding out new treatment and prevention targets for HF and AF. We know that LDL cholesterol is causally associated with ASCVD12. On the other hand, recent studies have suggested that apolipoprotein B (APOB)-containing lipoproteins, including remnant lipoproteins have been considered as so-called residual risk factors for ASCVD under the LDL-lowering therapies13. In addition, several studies have suggested that remnant lipoproteins are also associated with HF in addition to ASCVD14,15. Potential mechanisms by which remnant lipoproteins affect the progression of HF are 1) via progression of ASCVD16, 2) provocation of inflammation and coagulation17, and 3) association with valvular diseases18. However, few data exist regarding this matter among individuals under the primary prevention settings. Moreover, it remains unclear if remnant cholesterol is associated with AF. In this study we aimed to assess if remnant cholesterol assessed by a simple equation (total cholesterol minus HDL cholesterol minus LDL cholesterol) was associated with incident ASCVD, HF, and AF independent of other established risk factors, including LDL cholesterol among individuals under the primary prevention settings.