The right marginal artery of the heart is a branch of the right coronary artery. It branches off at the inferior border of the heart and passes to the left towards the apex. It passes horizontally, branching and tapering along its route. It supplies the right ventricle.
Occasionally, the right marginal artery may arise from a more proximal point along the right coronary artery. In this case, it passes to the apex obliquely across the surface of the right ventricle.