Chronic pneumonitis of infancy (CPI) is a very rare lung disease in infants and young children. We report a 33-day-old infant with CPI, focusing on the radiologic aspects of the disease. Chest radiographs showed variable and non-specific appearances including ground-glass shadowing, consolidation, volume loss, and hyperinflation. Dense alveolar opacities progressed as CPI advanced. The radiologic features of our case reflected pathologic changes.