PURPOSE: To analyze the clinical and radiological manifestations of pulmonary infection in patients with AIDS. MATERIALS AND METHODS: We reviewed the medical records and analyzed retrospectively analysed the chestradiographs (n=24) and CT scans (n=11) of 26 patients with AIDS who had been followed up at our institute from1987 to June 1998. Pulmonary infections were confirmed by sputum smear and culture (n=18), pleuralexamination(n=3), bronchoalveolar lavage (n=3), autopsy (n=4), transbronchial lung biopsy (n=1) or clinicalhistory (n=9). The study group included 23 men and three women aged 25-54 (average 35.2) years. We correlated theradiologic findings with CD4 lymphocyte counts. RESULT: Pulmonary infections included tuberculosis (n=22),Pneumocystis carinii pneumonia (n=9), cytomegalovirus (n=3), and unidentified bacterial pneumonia (n=2).Radiologically pulmonary tuberculosis was classified as primary tuberculosis (n=11 ; mean CD4 counts: 41.3cells/mm3) and post-primary tuberculosis (n=11 ; mean CD4 counts: 251.3 cells/mm3). CT findings of tuberculosisincluded lymphadenitis (n=6), bronchogenic spread (n=5), large consolidation (n=4), esophago-mediastinal fistula(n=2), and cavity (n=1). Tuberculosis in AIDS responded rapidly to anti-TB medication with complete or markedresolution of lesions within three months. Radiologic findings of Pneumocystis carinii pneumonia included diffuseground glass opacities, cysts, and reticular opacities. CONCLUSION: Tuberculosis was the most common infection inpatients with AIDS in Korea, and this is attributed to the high prevalence of tuberculosis. Radiological findingsvaried with CD4+ cell count, showing those of primary tuberculosis as a patient's CD4+ cell count decreased.Pulmonary tuberculosis in AIDS responded rapidly to anti-Tb medication.