As with all lemurs they are originally only found in Madagascar, however the Mongoose lemur has also been introduced to the nearby Comoros islands.

The mongoose lemur is active at different times of the day, depending on the season. During the wet months there is considerably more evening activity. With the onset of the dry season in May, there is a shift towards nocturnal behaviour.

The range of the mongoose lemur has probably always been limited but its range is now reduced to scattered patches of western dry forest.