There is interest in the impacts that climate change (CC) factors will have on the infection of staple food commodities by fungal diseases pre-harvest and by spoilage fungi post-harvest and the possible contamination with mycotoxins. It is essential to examine the effect of three-way interactions between elevated CO2 (350ppm versus 650-1200ppm), temperature increases (+2-+5°C) and drought stress on growth/mycotoxin production by key spoilage fungi in staple food commodities. This paper examines the available evidence on possible impacts on infection of key food commodities by mycotoxigenic fungi and whether mycotoxin contamination will increase or decrease due to CC scenarios. Examples are chosen from aflatoxin and fumonisin contamination of maize and trichothecene producing diseases of wheat. Acclimatization issues and regional effects are considered. The key questions which remain unanswered and the impacts on food security are discussed.