His mate can have access to the sperm packet. Lying quietly, the male allows her to maneuver her vent over the sperm packet and take it up in the lips of her cloaca. The mating process takes approximately half an hour, after which the female is released by the male and both go their separate ways.
The time from fertilization to the birth of the larvae is about ten months. Sometimes the sperm packet may be retained in the cloaca for several months, even though the winter, so that eggs may be fertilized at a more favorable time. The larvae develop full term in the eggs while still in the body of the parent, who will seek out a suitable body of water as soon as birth becomes imminent. Only cool streams and ponds in half shadow are selected. The female will search for a suitable shallow spot into which she can release up to 50 hatching eggs or newly hatched larvae. In certain cases, especially in the southern part of the range or where free water is scarce, the larvae may be retained right through metamorphosis and tiny replicas of the adults may be deposited.
At birth, the larvae are about 2.5 cm (1 in) in length and are colored somewhere between yellowish gray and brownish black. The body is usually speckled with little yellow spots, with a larger one at the base of each leg; the latter spot is a trademark of S. salamandra larvae and is not present in the larvae of related species.