Abstract： Background Factors of cell-mediated immunity and allergy together play their roles in the pathogenesis of pulmonary tuberculosis (PTB) and its prognosis. The purpose of this study was to investigate the computed tomographic demonstrations of HIV seropositive PTB and the relationship between its pathogenesis and CD4+ T-lymphocyte count.Methods The documented CT images of a total of 44 patients with HIV seropositive PTB, definitely diagnosed by etiological or pathological examinations, their clinical data and their CD4+ T-lymphocyte count were retrospectively reviewed.Results There were 15 cases of miliary tuberculosis, accounting for 34.1% of the total cases; 15 cases of nodular tuberculosis, 34.1%; 6 cases of ground-glass opacity, 13.6%; 5 cases of cord-liked fiber shadows, 11.4%; 16 cases of flaky and flocculating shadows, 36.4%; 5 cases of cavitation, 11.4%; 5 cases of tumor shadows, 11.4%; 2 cases of pleural thickening, 4.5% and 11 cases of pleural effusion, 25.0%; 1 case of calcification, 2.3%; 16 cases of lymphadenectasis,36.4%. The foci were located around the pulmonary hilum, anterior segment of superior lobe, basal segment of inferior lobe, medial lobe and lingual lobe. CD4+ T-lymphocyte count was closely related to the imaging demonstrations of HIV seropositive PTB.Conclusions CT scanning can demonstrate various signs of PTB. CD4+ T-lymphocyte level determines the variety of imaging demonstrations of HIV seropositive PTB and its prognosis.