AbstractBasal stem rot caused by Ganoderma boninense is the single major disease to affect oil palms in South Asia and Oceania. Although first described in commercial plantations some 90 years ago it remains a major constraint to oil palm planting, with disease occurence increasing with succesive plantings. There is a considerable volume of published research into the occurence, diagnostics and control of basal stem rot but much of this has been focused on individual plantings or local environments. In this manuscript we attempt to bring together reports from across the South Asia/Oceania regions to provide a comprehensive review of the current knowledge and to identify the key issues that still need to be addressed in order to achieve a comprehensive understanding of the disease and disease processes.