The mechanisms involved in the pathogenesis of melioidosis, caused by the intracellular bacterium Burkholderia pseudomallei, are unclear. C57BL/6 mice are resistant to infection, while BALB/c mice are highly susceptible. Previous studies have demonstrated that peritoneal exudate cell preparations enriched for macrophages are capable of effectively eliminating intracellular pathogens. In this study we present evidence showing that interaction of macrophages with lymphocytes is necessary for efficient anti-B. pseudomallei activity.