Melioidosis and leptospirosis are common tropical infectious diseases, but confirmed co-infection by both is rare. We describe a fulminant case of Burkholderia pseudomallei and Leptospira co-infection in a 29-year-old Malay lady with underlying uncontrolled type 2 diabetes mellitus, who had no obvious exposure to either organism. Despite close monitoring and aggressive treatment in the Intensive Care Unit (ICU), this patient eventually succumbed to death from the disease progression. As co-infections of melioidosis and leptospirosis can lead to a high mortality, suspicion of the diagnosis must always be raised especially in diabetic patients from endemic area, who present with sepsis of unknown origin, to allow for prompt initiation of appropriate treatment.