The slender grouper is a medium fish growing to a length of about 65 centimetres. The head occupies 40% of the total length and the mouth is large, with the lower jaw longer than the upper jaw. There are no palatine Teeth, a fact which distinguishes this species from other groupers. The basic colour is pale reddish-brown liberally dotted with orange spots which are closer together on the head. There are five pale silvery blue longitudinal lines running down either side, the lower 3 reaching the tail but the upper two breaking into irregular streaks. The dorsal fin has 11 spines and 14 to 16 soft rays. The anal fin has 3 spines and 8 to 9 soft rays. Juvenile fish have vivid blue and red longitudinal stripes.
Anyperodon leucogrammicus is a reef-associated, non-migratory species that inhabits coral rich areas (5 to 80 m) and clear waters on lagoon and seaward reefs.
The main diet of the Slender Grouper is probably small fishes, small cephalopods and crustaceans. They seem to be ambush predators who vary their diet according to location and availability and as with most groupers pretty much anything moving that can fit into their mouths they will have a go at. The slender grouper is carnivorous, feeding mainly on other fish such as goatfish but possibly also on invertebtrates. Juvenile slender groupers are aggressive mimics of the red-lined wrasse and the silty wrasse. They resemble them in appearance and in behaviour which lulls a potential prey fish into a false sense of security and enables the grouper to approach it without detection.
It is used in commercial fisheries of the Maldives.