This study aimed to investigate the status of primary liver cancers found through a routine health check-up. The data of subjects who were diagnosed with primary liver cancer for the first time through a routine health check-up during a period of 8-yr were analyzed. Primary liver cancers were detected for the first time in 34 subjects among 91,219 routine health check-up subjects. Only 11.8% of primary liver cancer subjects had been under previous surveillance. Of them, 55.8% were positive for HBsAg, 17.7% were positive for anti-HCV, and 8.8% were heavy alcohol comsumers. However, 17.7% of the subjects were neither heavy alcohol consumers nor positive for both HBsAg and anti-HCV. Of the subjects, 50.0% had a single nodular tumor, 23.5% had multi-nodular tumors, and 26.5% had an infiltrative tumor. A routine health check-up may provide beneficial opportunities to detect a liver cancer in a very early stage. It is beneficial to start surveillance in high-risk subjects for liver cancer or to detect any liver cancer in subjects without risk factors of chronic viral hepatitis or heavy alcohol consumption.