There have been few studies on the foods of Red deer (Cervus elaphus L.) and Roe deer (Capreolus capreolus L.) in British forests. Notable exceptions are the work of Prior (1968), Henry (1978) and Hosey (1981) on Roe deer. British work on the food of Red deer seems to have been confined to studies of animals on upland swards (Charles, McCowan & East, 1977; Staines ∓ Crisp, 1978). However, a more abundant supply of data on the food and feeding of both Red and Roe deer comes from the Continent (Dragoev, 1964; Gabuzov, 1960; Kolev, 1966; Novikov & Timofeeva, 1964; Siuda, Zorowski & Suida, 1969; Dzieciolowski, 1967a, b, 1969). Even so the data available were obtained from studies made on individual species of deer. This paper reports the results of an investigation into seasonal changes in the diet of Red and Roe deer coexisting in a conifer forest in the east of England.