A survey of entomologists was conducted to estimate the value of present and potential losses from invertebrate pests for the six most important Australian grain crops: wheat, barley, oats, canola, lupins and grain sorghum. The survey provided data on the incidence and severity of 29 invertebrate pest groups across the six crops. These data were combined with crop production data to estimate the value of the losses in the northern, southern and western production regions of Australia. Aggregated across the six major Australian grain crops, the estimated present annual loss because of invertebrate pests totalled $359.8 million. The relative importance of invertebrate pests varied between regions. Nationally, the five most important invertebrate pests based on estimated present losses aggregated across the six crops were redlegged earth mite ($44.7 million), budworms ($36.3 million), blue oat mite ($35.5 million), lucerne flea ($28.4 million) and locusts ($28.4 million). Present cultural and pesticide controls of invertebrate pests effectively reduced losses, but pest management remained very dependent on pesticides. Nationally, pesticide treatment costs aggregated across all six crops totalled $159.1 million. Based on pesticide treatment costs, the three most costly invertebrate pests were various species of aphids ($28.0 million), redlegged earth mite ($20.5 million) and various species of budworms ($16.9 million). Results from this study will inform future investment decisions related to invertebrate pests.