More than 2900 faecal samples and 200 herbage samples were examined from January 1986 to January 1989 during a study of the host/parasite relationships of the gastrointestinal nematodes of a herd of farmed red deer in Surrey. The pattern of faecal egg output from the hinds appeared to conform to a tri-modal distribution with peaks during spring, the periparturient period and late summer. Third stage larvae were present on the herbage during every month. The new generation appeared in June but levels of larvae remained low until the autumn. The implications of these findings are discussed in relation to the farming of red deer.