This common species occurs throughout Southeast Asia in virtually all habitats including urban areas where it may sometimes be seen feasting on roadkill. It is particularly common, however, in mangrove areas as it is a strong swimmer and it can flourish on a diet of crabs and other large invertebrates.
It can remain submerged underwater for a considerable time. It is also an agile climber, and a raider of bird's nests. The Malayan Water Monitor is distinguished from other monitors by the position of the nostrils, which lie near the tip of the snout.