Chlamydia trachomatis is a common cause of subacute, afebrile pneumonia with onset from 1 to 3 months of age. On physical examination, crepitant inspiratory rales are commonly heard. Infiltration is usually bilateral and interstitial; reticulonodular pattern and atelectasis have also been described, which distinct the disease from miliary tuberculosis. We report an infant who had a disseminated miliary pattern in the chest radiograph and computed tomographic scan of the thorax that was diagnosed as Chlamydia pneumonia with serologic investigations. We emphasized that Chlamydia trachomatis can cause a miliary reticulonodular pattern in radiological examinations of infants who were admitted with respiratory symptoms. We suggest that pneumonia due to C. trachomatis should be kept in mind in the differential diagnosis of infants examined because of a diffuse miliary pattern.