Since 1985 increasingly more foxes have been recorded from cities in Switzerland. The inquiry of town officials showed that foxes are observed in 28 out of the 30 largest Swiss cities today and breeding dens are known in 20 of these cities. Urban foxes are observed more often than one would expect in larger cities than in smaller towns. In Ziirich, the largest city in Switzerland, urban foxes were very scarce until the early 1980s. According to the hunting statistics, from 1985 onwards, there was a drastic increase in the urban fox population. I n the adjacent rural areas, there was also a clear but less extreme increase in the fox population from 1984 onwards due to successful vaccination campaigns against rabies. As an explanation for the presence of foxes in human settlements we suggest two alternative hypotheses, which focus either on the population pressure in the rural areas or on the behavioural adaptations of urban foxes. The presence of foxes in urban areas influences behaviour and attitudes of people towards urban wildlife and it has a consequences for the management of foxes and the treatment of zoonoses such as rabies and the alveolar echinococcosis.