Although concurrent bacterial infection was shown to have a major influence on mortality in previous influenza pandemics [4] , its' role in the current H1N1 pandemic is still evolving. Recent postmortem studies amongst fatal H1N1 cases established a link between bacterial lung infections and increased deaths [13] . Whilst an earlier study showed bacterial coinfection not to be a major contributor to severe disease [12] , a more recent study demonstrated otherwise [8] . In our study, patients with bacterial coinfection were found to have higher risk of developing complications. The presence of underlying comorbidity, liver impairment and supplemental oxygen requirement were significantly higher in bacterial coinfected patients in univariate analysis, although these factors were not predictive in multivariate analysis.