The Radiology approach to diffuse infiltrative lung disease (DILD) is based on a chest radiography and CT. Chest radiography can categorize DILD into five main patterns of abnormality: linear, reticular, cystic, nodular, and ground-glass patterns. The CT patterns of DILD can be classified into six patterns including thickened interlobular septa, reticular, cystic, nodular, ground-glass, and consolidation patterns. The pertinent differential diagnosis of DILD is based on the pattern recognition approach of abnormalities, and a specific diagnosis can often be made using chest radiography and CT. This pictorial essay illustrates the radiology pattern recognition approach for DILD using chest radiography and CT.