To investigate the epidemiology and outcome of adult community-acquired pneumonia (CAP) in tropical Australia. A prospective study was performed of all adult patients with CAP admitted to the Royal Darwin Hospital, a major hospital in tropical northern Australia. A standard definition of CAP was used and data collected on demographics, risk factors, history, examination, investigations, treatment and outcome. Locally-developed treatment guidelines were used. One hundred and sixty-seven adults were included in the analysis. Aboriginal people were over-represented, younger and were more likely to have risk factors for CAP. The most frequent pathogens isolated were Streptococcus pneumoniae and Burkholderia pseudomallei. 'Atypical pneumonia' organisms were uncommon. Treatment guidelines included penicillin for mild pneumonia but emphasised coverage of Burkholderia pseudomallei in those with risk factors, especially during the monsoon season. The mortality rate from pneumonia was low with three deaths in 167 cases (1.8%). International guidelines for the management of CAP have been based on populations and organisms from temperate regions and may not necessarily be applicable to tropical regions. Guidelines based upon local epidemiology must therefore be developed. This study illustrates how mortality can be minimised using a process of determining local CAP etiology, developing treatment guidelines and auditing patient management.