Investing in pre-breeding for exotic pests and diseases in cereals is characterised as investing in an option of preparedness regardless of whether an incursion occurs. The return to pre-breeding depends on the likelihood of pest arrival, its spread across cereal producing regions and how damaging it will be through time. Any delay in the release of resistant varieties after an incursion translates into yield losses, chemical costs and, for some pests and diseases, price discounts. However, returns to pre-breeding investment are limited by delay time without pre-breeding, management alternatives and the adoption rates for resistant varieties by producers. Our analysis has estimated returns to investment for pre-breeding for six high priority exotic wheat and barley pests and diseases. The methods developed here allows for regional disaggregation and regional pest suitability across Australia’s cereal production landscape. Results indicate that pre-breeding investment is viable for only half of the pest and diseases studied. The relatively high return to these can be explained by significant yield effects, rapid spread and widespread pest suitability across regions. Furthermore, a higher average yield loss can offset lower incursion probability. In contrast, those not viable are due to slow spread, small or erratic yield effect and biosecurity trade issues not addressed by resistance. Investing in pre-breeding is highly risky as the modal investment return for all pests and diseases is zero and returns to breeders are short lived.