An epidemiological study has been made of virus warts on the hands of all workers in a large meat processing factory. The meat handled is pork and beef. A total of 1141 employees were examined, 687 of whom were constantly handling meat. The plant outline and the work of the 144 workers in the butchery section are described in detail. The prevalence of warts in meat handlers was 33.6-70.4% in different sections. The prevalence in non-meat handlers varied from 18.2% to 44.4%. Half of the employees with warts were unaware of them, particularly in regard to plane warts.