There are two genera and four species of viscacha.
- Plains viscacha (Lagostomus maximus): Lives in the Pampas of Argentina and Chile. It can be easily differentiated from other viscachas because it has black and gray mustache-like facial markings. This species lives makes colonies. It lives in warrens of ten to over one hundred. It is very vocal and emits alarm calls. The plains viscacha can strip grassland used to graze livestock; this caused ranchers to consider the rodent a pest species.
- Northern viscacha (Lagidum peruanum): Native to the Peruvian Andes at those elevations between the timber line and the snow line. It is dorsally gray or brown in color. It has a bushy tail and long, furry ears. This species lives in large colonies. The colonies are separated into individual family units, like an apartment complex. It eats a wide range of plats. It lives in a harsh, rocky environment. Therefore, it is not too picky about the food.
- Mountain viscacha (Lagidum viscacia): Also called southern viscacha, this species is similar to the northern viscacha, but its fur is more red in color. It lives in similar habitat in the Andes.
- Wolffsohn's viscacha (Lagidum wolffsohni): Little is known about this species, as it is rarer than the other three viscachas.