Beneficial invertebrates (predators and parasitoids) can make significant contributions to the suppression of insect pest populations in many cropping systems. In Australia, natural enemies are incorporated into integrated pest management programs in cotton and horticultural agroecosystems. They are also often key components of effective programs for the management of insect pests of grain crops in other parts of the world. However, few studies have examined the contribution of endemic natural enemies to insect pest suppression in the diverse grain agroecosystems of Australia. The potential of these organisms is assessed by reviewing the role that natural enemies play in the suppression of major pests of Australian grain crops when they occur in overseas grain systems or othere local agroecosystems. The principal methods by which the efficacy of biological control agents may be enhanced are examined and possible methods to determine the impact of natural enemies on key insect pests are described. The financial and environmental benefits of practices that encourage the establishment and improve the efficacy of natural enemies are considered and the constraints to adoption of these practices by the Australian grains industry are discussed.