As radiological imaging has progressed, smaller nodules are more frequently detected. The trend of minimal invasiveness in thoracic surgery has paved the way for video-assisted thoracic surgery. In localization for small nodules and segmentectomy for such nodules, fluorescent dyes, such as indocyanine green (ICG) have been used more often. Therefore, we herein describe the utility of fluorescent imaging in the treatment of lung cancer, which is currently the mainstream of thoracic surgery, focusing on the clinical application of ICG.