Thromobocytopenia predicts mortality in patients with melioidosis in Thailand. We analyzed platelet counts in two large cohorts of melioidosis patients in tropical northern Australia to assess utility in a different clinical setting. Admission platelet counts were compared between subgroups of patients with different clinical outcomes. Patients with more severe disease (indicated by bacteremia, septic shock, and death) had significantly lower platelet counts than those with less severe disease. Logistic regression analysis was carried out for potential predictors of mortality among various clinical parameters, and platelet count was shown to be an independent predictor of mortality. Furthermore, in patients critically ill with melioidosis, an increasing platelet count after admission was associated with a significantly greater chance of survival. However, given that most patients with severe disease still had platelet counts within the normal range, platelet count is not a useful biomarker for predicting the severity of melioidosis in a clinical context.