Amphibians are the group of animals suffering particularly from the presence of roads and vehicle traffic. The seasonal migration to breeding places undertaken by amphibians in the temperate climate zone is the main reason for their appearance on roads. Between June 2001 and August 2003, 957 common toads Bufo bufo were recorded killed on 48.8 km road network with various traffic volumes (350-10500 cars per 24 h), situated in the agricultural landscape of south-western Poland. The highest mortality was recorded in April (57% of all road-kills). The places with highest recorded mortality varied markedly throughout the year. In spring, many more animals died within the built-up areas, while in summer and autumn their number increased in the open countryside. During the whole study period, 73% of all road-kills were recorded on roads (55% of all controlled) with the lowest traffic volume (350-470 cars per 24 h). The average number of road-kills on roads with the high traffic volume (5700-10500 cars per 24 h) was over 15 times lower than on the roads with low traffic (0-0.17 road-kills per 100 m on roads with high traffic vs 2.59 road-kills per 100 m on roads with low traffic). The number of road-kills on 15 road sections was most closely related to the abundance of local populations of Bufo bufo and to the size of water bodies situated in the road vicinity. The yearly level of local mortality in breeding populations of Bufo bufo due to the vehicle traffic ranged from 2 to 18%.