A postal questionnaire was used to collect information on the prevalence of lice on cattle on a random sample of dairy farms in England and the bordering counties of Wales. Replies were received from 1040 (52.8 per cent) of the 1970 farms which were mailed. Fifty per cent of farmers reported having ever seen or suspected lice in their herds and 29 per cent reported possible infestations in the winter of 1996/97. Visits were made to 24 farms in the south west of England during February 1998. Twelve of the farmers said that they had seen or suspected lice in their herd since October 1997, and that lice were more frequently observed on the adult cattle. However, examination revealed lice on 18 of the 24 farms, and adult cattle were the least likely group to be infested.