The New Guinea slender rat is a medium-sized, narrow-bodied rat of hill and lower montane forests. Examined stomachs contained many insects and a small amount of seeds. Available breeding records suggest a pause around midyear and a restart around November.
It is medium-sized and slender. The back is dark brown; dorsal fur ranges from soft and sleek to distinctly woolly with altitude. Gray belly hairs are tipped white or buff, and some animals have a pure-white chest patch. The tail is nearly always white-tipped and may be longer or shorter than the head and body.
It uses underground nests, which are said to have one entrance. Examined stomachs contained many insects and a small amount of seeds. Available reproductive data suggest breeding stops around midyear and resumes around November.
An extinction-risk assessment has not been added yet.