A series of laboratory and field experiments was carried out to assess the effect of exposure to dry heat on Colletotrichum lupini infection in lupin seed. Seed infection was significantly reduced by exposure to 60°C to 80°C. Infection was undetectable in 1000 seeds after 1 day at 80°C, 1–4 days at 70°C or 8 days at 65°C. Germination of Lupinus angustifolius (cv. Belara) seed was not affected by 7 days at 60°C or 4 days at 65°C. Seven days at 70°C or 80°C reduced germination by ~15%. Effects of heat treatment on seed germination varied across seed lots tested. Moderate periods of exposure to dry heat are an effective way of reducing seed infection to extremely low or undetectable levels.