One of the most important recent advances in imaging technology for the diagnosis of lung cancer is CT consisting of high-resolution and helical volumetric techniques. CT has made a detailed morphological analysis correlated with histopathology as well as the detection of small peripheral lung cancers possible. MRI still remains as a complementary role to CT, but MR angiography using fast gradient-echo technique has achieved a great progress. FDG-PET is the most encouraging development in nuclear medicine and is vigorously evaluated for its cost-effective clinical value in differentiating benign and malignant nodules as well as in staging of lung cancer. In chest radiography, the development of computer-aided diagnosis is underway and seems promising.