Amphibians often cross roads when migrating in the course of a year. In the canton of Aargau 86 such migrating sites are known. Between 1989 and 1998 twelve of them have been watched, whereby altogether about 187 000 Rana temporaria, 90 000 Bufo bufo and 19 000 newts (mostly Triturus alpestris) have been registered and the data evaluated. It was between February 24 and April 12 that 90 % of all the amphibians watched migrated to their breeding grounds.