The least praomys is a small mouse recorded at scattered sites south and west of the Congo River, in forest, fields, and cropland. It is active at night on the ground.
The back is dark brown in younger animals and warm brown in older ones, with paler flanks and a whitish-gray underside. The tail is very long and almost naked.
It has been recorded in primary and secondary forest as well as fields and cropland. It is nocturnal and terrestrial; the cited account has no information on its diet or breeding.
An extinction-risk assessment has not been added yet.