Vipera aspis is a moderate-sized snake, growing to an adult length of between 70 to 90 centimeters, with a relatively thick body. Males are normally larger than females. The snake is distinguished by its broad triangular head, delineated from the body by a covering of small scales, and by its vertical pupils. The dorsal markings vary between individuals and sub-species but in general take the form of a dark brown or black zigzag. This species is viviparous. When threatened, it will hiss and make small forward jerking motions with its head.

Vipera asps can be found throughout many countries north of the Mediterranean, particularly France, Andorra, northeastern Spain, extreme southwestern Germany, Italy, Switzerland and northwestern Slovenia. It is particularly common at moderate altitudes within the Alps and Pyrenees. It favors warm, dry environments such as south-facing rocky surfaces and river banks exposed to the sun. However, it is also to be found in marshy areas or woodlands.

Like all members of the Viperidae, Vipera aspis is venomous, armed with poison glands connected to curved fangs which enable it to inject venom deeply into the tissues of its prey, which typically comprises small mammals or fledgling birds. At rest the fangs lie towards the back in folds of skin within the mouth. The venom contains a hemotoxin which causes cardiac arrest in the victim.

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