A survey of yield losses in yams caused by soil pests showed that, of a wide variety of organisms causing damage, only termites (Amitermes), yam beetles, nematodes and various ‘rots’ caused significant losses. Damage was a poor indicator of yield loss which was estimated by assessing monetary values of damaged and undamaged tubers. A total of 114 farmers were surveyed during 1976–1977 in eight villages, two each in the Mokwa, Lokoja (Guinea savanna), Onitsha and Aba (forest) areas. The percentage of farmers sustaining total losses exceeding 8% in these areas was 10%, 8%, 2% and 35% respectively. The maximum losses sustained by individual farmers were 29% forAmitermes, 42% for yam beetle, 29% for nematode (Scutellonema) and 6% for ‘rots’ and all of these were from Obegu village near Aba. A trial using 2.5% aldrin dust to treat setts indicated that the increase in yields resulting from decreased damage byAmitermesand yam beetle would be profitable for 92–100% of farmers in Obegu, 24% in Ibere (both near Aba), 20% in each of the two Mokwa villages and none in the other villages.