Mating takes place during the short breeding season in slow or moving water, but thereafter the Marbled Newt spends its life on dry ground. Like the axolotl, Marbled Newts have the power of regenerating missing organs. Colouring is ventrally orange and dorsally grey marbling, and in addition males have blue sides and a low crest. Once they leave the water in summer, males lose the crest and the skin of both sexes takes on a warty appearance. Thereafter the Alpine Newt lives on dry land until autumn, when it hibernates for the winter.
Females are normally larger than males.
If picked up, these newts can make a whistling sound by inflating themselves and releasing the air. This species is also capable of regeneration of limbs. Occasionally larvae do not complete their metamorphosis by autumn, in which case they hibernate and metamorphose the following year. Neoteny has also been occasionally recorded. It is also the most aquatic, being found in still- or slow water at low altitude and sometimes at much higher altitudes.