Project PHT/1990/035, ‘Integrating Grain Protectants into Storage Pest Management’ was supported by ACIAR for nearly four years from 1992 to 1995. The project was based in China and Australia. Project activity within Australia included the further enhancement of an expert system that had been developed by CSIRO. Three main activities took place within the project in China: assessing the extent of resistance to the most commonly used grain protectant, malathion; determining the rates of fenitrothion and deltamethrin that might be used under Chinese storage conditions in order to improve the range of protectants available for Chinese grain storage; and adaptation for, and extension of, an Australian expert system in China. Resistance to malathion was assessed to be serious, guidelines for the use of fenitrothion and deltamethrin were developed, and a start was made on adapting the expert system to Chinese conditions. Most of the benefits from the project will accrue to China through the knowledge gained from the project on the management of the new protectants and the further development of the expert system. Potential benefits to Australia were limited by the change in market requirements in Australia from the mid 1990s, whereby grain was required to be both insect and chemical free, thereby ending the use of protectants here. The investment analysis shows that the benefits from the project are significant, largely because of the very large amount of grain produced and stored in China. While protectants are not used on a high proportion of grain stored there, the new protectants are being used more rapidly and effectively than they would have been without the project. The net present value of the project at a 5% discount rate is estimated at $10.1 million, the benefit–cost ratio at 7 to 1 and the internal rate of return at 43%. The net present value is still positive ($3 million) even if only benefits up to 1999 are considered.