The aim of this study was to identify factors associated with current HIV (human immunodeficiency virus) testing practice at Port Moresby General Hospital and positive serostatus among children tested, as a basis for contributing to guidelines on HIV testing for children in Papua New Guinea. Data were extracted from hospital records to determine the demographic and presenting clinical characteristics of admitted children tested for HIV serostatus between 1 December 2005 and 30 November 2006. These data were compared with corresponding data from untested control children from the same wards. The same characteristics were compared between seropositive and seronegative cases. Odds ratios were derived for potential predictors of testing and its outcome. During the study period, HIV tests were reported on 215 children, of whom 57 were seropositive. Controls were 264 untested children. Tested children were more likely to be aged 18 months or less, to have been admitted for more than 7 days, and to have diarrhoea, be malnourished or have oral candidiasis. Among children tested, suspected tuberculosis as a presenting illness was significantly predictive of HIV-positive serostatus. This study indicates that certain clinical factors associated with HIV-positive status in children may not yet have been incorporated into testing practice, and underlines the importance of developing a systematic approach to testing children for HIV in Papua New Guinea.