Mongoose Lemurs are dull brown with white cheeks. The head and body length is 300-450 mm with tails about the same length. They have soft fur with a pronounced ruff around the neck and ears. They are arboreal, using all fours to run and leap among branches. They are mostly diurnal but some specific groups are nocturnal in Madagascar and Comoros.

The diet of the mongoose lemur mostly consists of fruits, flowers and leaves.

Some permanently bonded pairs have been observed with no more than two young. Vocalizations are well developed with greeting calls, territorial expression, threats, and alarms. Mongoose lemurs mate from April to June with gestation of about 4.5 months. Births occur just before the rainy season. Usually there is one young, but sometimes twins are born. The infant clings to the mother's underside the first four weeks and then move to a spot on her back.

They are found in NW Madagascar, between Majunja and Betsiboka; Anjouan, and Moheli (Comoro Isls).