Hepatocellular carcinoma (HCC) is usually known to develop in patients with underlying high-risk liver diseases such as viral hepatitis, cirrhosis and alcohol abuse, whereas reports dealing with HCC in Crohn's disease (CD) are limited. We present a case of HCC, which developed sequentially within a short period in a 52-year-old Japanese man with a 36-year history of CD without risky conditions for HCC. He also had not taken immunosuppressants such as azathioprine. Although the definitive etiological factors contributing to hepatocarcinogenesis in the present case could not be elucidated, further close surveillance is required.