Two hundred eighty-eight patients hospitalized with severe community-acquired pneumonia (CAP) were followed for 28 days in a prospective multicenter study. At day 7, 25% of patients had resolution of CXR abnormalities and 56% had improvement. At day 28, 53% of patients had resolution of CXR abnormalities and 78% had clinical cure. By multivariate analysis, delayed resolution of CXR abnormalities by day 7 was associated with multilobar disease, dullness to percussion by physical exam, elevated CRP (> 200 mg/L), and tachypnea (respiratory rate > 25/min.) on admission.