We reviewed chest radiographs of 57 HIV-infected patients with pulmonary diseases in whom Streptococcus pneumoniae was the sole respiratory pathogen isolated to evaluate whether highly active antiretroviral therapy (HAART) or bacteremia modify radiographic appearance. Pneumococcal lung disease presented as lobar pneumonia in 40% of the cases, 54% of whom were on HAART; as bronchopneumonia in 42%, 58% on HAART; as interstitial infiltrates in 17%, 60% on HAART. Bacteremia was observed 38 times in 23 patients with CD4 less than 200/mm(3), and in 15 with CD4 greater than 200/mm(3) (p > 0.05). HAART does not significantly influences radiographic appearances of lung disease caused by Streptococcus pneumoniae (p > 0.05). Immunosuppression induced by HIV infection was a major risk factor for development of pneumococcal lung disease (p = 0.04) and influences radiographic appearance; bronchopneumonia (p = 0.006), in particular multifocal (p = 0.008), which was more frequent in subjects with CD4 less than 200/mm(3). Bacteremia influences radiographic appearance of pneumococcal lung disease; lobar pneumonia was more frequent (p = 0.003), and considering CD4 cell count, was more frequent if CD4 cell count was above 200/mm(3). An original finding of this study was the frequency of interstitial changes. This pattern of pneumonia, found in 17% of our patients, could represent a difference between HIV-seropositive and -seronegative subject in displaying pneumococcal lung disease.