Some reports suggest the positive correlation between Schistosoma japonicum infection and colorectal cancer, however the sufficient evidence that supports a causal relationship between them has not been established. Japan used be an endemic area of S. japonicum infection for 40 years ago. But now all of Japan is a non-endemic area of S. japonicum infection. We report a case of ascending colon cancer associated with deposited ova of S. japonicum in non-endemic area.