Most of the adult porcupinefishes are found inshore and most of the juveniles are pelagic. They are found on rocky and coral reefs, and over sand, weed, or sponge-covered bottoms to depths of 150 m. They feed on hard-shelled benthic invertebrates which are crushed with their powerful beak-like jaws. Most adults are solitary and nocturnal. They are thought to have toxic flesh.
There are 7 genera and about 18 species worldwide. Malaysia has about 4 species.