The species is very close to the European polecat in general appearance, proportions and habits, though its body seems somewhat more elongated, due to its shorter guard hairs.
The tail is short, constituting a third of its body length.
The skull is heavier and more massive than that of the European polecat, having more widely spaced zygomatic arches and more strongly developed projections, particularly the sagittal crest.
It greatly resembles the black-footed ferret of North America, with the only noticeable differences between them being the steppe polecat's much longer and softer fur, shorter ears, and shorter postmolar extension of the palate.
It has four pairs of teats and well-developed anal glands, which can produce a sharp-smelling liquid which is sprayed in self-defence.
Males measure 320–562 mm in body length, while females measure 290–520 mm.
Tail length of males is 80–183 mm and 290–520 mm for females.
Males in Siberia may weigh up to 2,050 grams, while females weigh 1,350 grams.
One giant polecat from Semirechye had a body length of about 775 mm.
Overall, specimens exhibiting gigantism are more common than in the European polecat, and occur primarily in western Siberia, where they likely hybridise with Siberian weasels.

The winter fur is soft and tall, with short, dense underfur and long, sparse guard hairs.
The fur is generally shorter and not as thick as that of the European polecat.
The guard hairs are especially well developed on the lower back, though still sparser than those of the European polecat.
Contrary to the former, the steppe polecat's guard hairs never completely cover the underfur.
The base colour of the winter fur is very light yellowish or whitish-yellowish.
The tips of the guard hairs are blackish-brown or brown, forming a frosting effect over the yellow underfur.
This frosting is stronger in the middle and lower back, where the guard hairs are denser and longer.
The guard hairs on the upper back, the flanks, between the shoulders and along the upper neck are extremely short, thus being lighter in colour than the posterior region.
The head is piebald, with the eye region and the upper side of the nose being covered by a brownish mask.
Behind the mask, a white band crosses the head from cheek to cheek.
A small brownish area is usually located in front of each ear.
The ears are completely white, while the throat is yellowish-white or almost white.
Sometimes, the head is entirely white.
The lower surface of the neck is dark blackish-brown or brown, while the chest and forelegs are black or blackish-brown.
The abdomen is light, yellowish-straw in colour.
The groin is the same colour of the forelimbs.
The base of the tail is light in colour, while the tip is dark brown.
The summer coat is shorter and coarser than the winter fur, and is not as dense and close-fitting, with a more strongly developed ochreous or reddish tone.
The head is, overall, darker than in winter, with greater contrast between the dark and white tones.
The species is very close to the European polecat in general appearance, proportions and habits, though its body seems somewhat more elongated, due to its shorter guard hairs. The tail is short, constituting a third of its body length. The skull is heavier and more massive than that of the European polecat, having more widely spaced zygomatic arches and more strongly developed projections, particularly the sagittal crest. It greatly resembles the black-footed ferret of North America, with the only noticeable differences between them being the steppe polecat's much longer and softer fur, shorter ears, and shorter postmolar extension of the palate. It has four pairs of teats and well-developed anal glands, which can produce a sharp-smelling liquid which is sprayed in self-defence. Males measure 320–562 mm in body length, while females measure 290–520 mm. Tail length of males is 80–183 mm and 290–520 mm for females. Males in Siberia may weigh up to 2,050 grams, while females weigh 1,350 grams. One giant polecat from Semirechye had a body length of about 775 mm. Overall, specimens exhibiting gigantism are more common than in the European polecat, and occur primarily in western Siberia, where they likely hybridise with Siberian weasels.
The winter fur is soft and tall, with short, dense underfur and long, sparse guard hairs. The fur is generally shorter and not as thick as that of the European polecat. The guard hairs are especially well developed on the lower back, though still sparser than those of the European polecat. Contrary to the former, the steppe polecat's guard hairs never completely cover the underfur. The base colour of the winter fur is very light yellowish or whitish-yellowish. The tips of the guard hairs are blackish-brown or brown, forming a frosting effect over the yellow underfur. This frosting is stronger in the middle and lower back, where the guard hairs are denser and longer. The guard hairs on the upper back, the flanks, between the shoulders and along the upper neck are extremely short, thus being lighter in colour than the posterior region. The head is piebald, with the eye region and the upper side of the nose being covered by a brownish mask. Behind the mask, a white band crosses the head from cheek to cheek. A small brownish area is usually located in front of each ear. The ears are completely white, while the throat is yellowish-white or almost white. Sometimes, the head is entirely white. The lower surface of the neck is dark blackish-brown or brown, while the chest and forelegs are black or blackish-brown. The abdomen is light, yellowish-straw in colour. The groin is the same colour of the forelimbs. The base of the tail is light in colour, while the tip is dark brown. The summer coat is shorter and coarser than the winter fur, and is not as dense and close-fitting, with a more strongly developed ochreous or reddish tone. The head is, overall, darker than in winter, with greater contrast between the dark and white tones.
Steppe polecat