Melioidosis is a common community-acquired infectious disease in northeast Thailand associated with overall mortality of approximately 40% in hospitalized patients, and over 70% in severe cases. Ceftazidime is recommended for parenteral treatment in patients with suspected melioidosis. Meropenem is increasingly used but evidence to support this is lacking. A decision tree was used to estimate the cost-effectiveness of treating non-severe and severe suspected acute melioidosis cases with either ceftazidime or meropenem. Empirical treatment with meropenem is likely to be cost-effective providing meropenem reduces mortality in severe cases by at least 9% and the proportion with subsequent culture-confirmed melioidosis is over 20%. In this context, treatment of severe cases with meropenem is likely to be cost-effective, while the evidence to support the use of meropenem in non-severe suspected melioidosis is not yet available.