Although the progress in understanding human genetics regarding cancer has been applied to the medical practice of treating hereditary cancers in developed western countries, it is not widely implemented in Japan. We started treating hereditary cancers at NHO Shikoku Cancer Center in November 2000. Our institution has a multidisciplinary team that provides medical care and genetic counseling for patients with hereditary cancers, and their relatives. The team consists of doctors from several related departments, and paramedics including a genetic counselor who participated as of 2009. Medical care of patients with hereditary cancers should not be separated from general oncological practice, but incorporate all medical professionals, including doctors of related departments and paramedic. We have attempted to identify patients with hereditary cancer and their family members and relatives at high risk; we followed them up and provided risk-reducing therapies for them at our cancer center. Here we present the framework of our practice in treating hereditary cancers. We discuss appropriate goals and future perspectives in the field of hereditary cancer in Japan.