Some acute bacterial infections, notably those caused by the pneumococcus and the non-typhi salmonellae, have not traditionally been considered as leading diseases in tropical medicine, despite their ubiquitous distribution and impact on health. The HIV/AIDS epidemic is forcing a re-evaluation of this position because of their importance in immunosuppressed adults, particularly where exposure is high and treatment relatively inadequate. The problem of acute bacterial disease in HIV/AIDS is outlined in industrialised countries and contrasted with the problem in tropical countries. Specific insights into HIV-related pneumococcal disease and non-typhi salmonellosis that have come from work in the tropics are then discussed. These infections need now to be recognised as an important element of tropical medicine.