Parastemon grandifructus is a tree in the family Chrysobalanaceae. The specific epithet ' is from the Latin meaning 'large fruit'.
Parastemon grandifructus grows up to tall with a trunk diameter of up to . The ellipsoid fruits measure up to long.
Parastemon grandifructus is endemic to Malaysian Borneo. Its habitat is lowland forests, including swamps, from sea-level to altitude.