Between 1996 and 2002, 162 cases of pulmonary melioidosis were reported from Srinagarind Hospital, Khon Kaen, northeast Thailand, 90 acute vs 72 subacute/chronic. Patients averaged 50 years of age and half worked as farmers. The male to female ratio was between 2 and 3 to 1 depending on the subgrouping. Burkholderia pseudomallei was confirmed by a culture or a four-fold rise in titer in the majority of cases, while the others were presumptive diagnoses based on response to treatment. Pulmonary melioidosis presented as either acute fulminant pneumonia or as an indolent disease. The common concurrent medical illness was diabetes mellitus. Mean incubation of the acute vs the sub-acute/chronic form was 8.7 vs 54.4 days, respectively. Leukocytosis was detected in 70% of cases. Sputum Gram's stain was not sensitive for diagnosis. Sputum culture and blood culture were diagnostic for 31.1 vs 22.2 and 40 vs 37.5% of the acute vs subacute/chronic forms, respectively. The common radiographic patterns for acute pneumonia were localized patchy alveolar infiltrate or hematogenous pattern. A bilateral diffuse patchy alveolar infiltration or multiple nodular lesions characterized the latter. Upper-lobe involvement with early cavitation and rapid progression were common. In the subacute/chronic forms, the radiographic pattern sometimes mimicked tuberculosis, with upper lobe involvement, patchy alveolar infiltrate with cavities or fibroreticular lesions. In approximately 30% of cases, liver and/or splenic abscess were common sites of extrapulmonary infection. Respiratory failure and septic shock from acute pulmonary melioidosis was 20% fatal. Early empirical antibiotic therapy should be given for severe pneumonia.