Malaria and HIV/AIDS are two of the most important infectious diseases worldwide, and although there is good evidence of a biological interaction between them, research into malaria and HIV continues to be largely separate. Furthermore, despite the fact that malaria and HIV/AIDS prevention and control programmes are being scaled up, they continue to be planned separately, despite having a substantial impact on one another. The authors of an editorial in the British Medical Journal therefore conclude that it is time for the development of a comprehensive operational research and policy strategy to tackle key knowledge gaps regarding malaria and HIV co-infection (1). This in turn will support the integration of interventions for both diseases, maximising their impact and cost effectiveness. Health systems can then be strengthened rather than overloaded within the typically “vertically” managed worlds of malaria and HIV/AIDS prevention and control.