Small cell lung cancer is the most aggressive tumor among lung cancers and has a greater tendency to be widely disseminated by the time of diagnosis. Without treatment, the median survial time of small cell lung cancer patients is only 2~4 months. However, though spontaneous regression of the malignant tumor has been frequently reported, spontaneous regression of the small cell lung cancer is rare. In this study a spontaneous regression of the small cell lung cancer is reported, along with a brief review of the literature. A 69 year-old woman was admitted for an evaluation for dyspnea. A chest roentgenogram obtained on admission revealed an abnormal mass shadow at the right hilus. She was diagnosed as having small cell lung cancer through a bronchoscopic biopsy. However this tumor regressed spontaneously without specific treatment after 12 months.