Alytes obstetricans mates on land, which is unusual among European frogs and toads. The male manoeuvres the string of large eggs onto his hind legs and winds it into a bundle. He then continues his normal terrestrial life, sheltering under stones by day, with the clutch attached.
Carrying lasts roughly three to six weeks. If conditions dry out, the male soaks the eggs by visiting damp ground or shallow water. When development is complete he enters a pond or trough and the tadpoles hatch and swim free. Terrestrial carrying keeps the eggs away from aquatic predators and from the fungal and bacterial infections that kill clutches left in water, and a male may carry more than one clutch from different females.
The species has a place in scientific history through the Austrian biologist Paul Kammerer, who in the 1920s claimed midwife toads inherited acquired characteristics after being forced to breed in water. The specimen at the centre of the claim was later found to have been injected with Indian ink, and the work is treated as discredited.