Sweetpotato (Ipomoea batatas) is a vital crop for overcoming food insecurity in sub-Saharan Africa and its production is highest in East Africa where yields are high and the growing seasons are short. This cross-country study assessed farmers’ local practices and their knowledge of the biotic constraints to sweetpotato production in Uganda, Rwanda, Kenya and Tanzania. The main constraints to production reported were pests, drought, diseases and the lack of disease-free planting materials. Farmers recognised the signs and symptoms associated with sweetpotato diseases on leaves, root tubers and whole plants, but were unable to assign the disease type (bacterial, fungal or viral).