Using data from the Osaka Cancer Registry, we calculated age-standardized cancer mortality rates among Koreans and Japanese living in Osaka, Japan, during 1968-77. The following points were elucidated: 1) Among Koreans in Osaka, the mortality rate for liver cancer was about twice that among Japanese; 2) Among Koreans in Japan, the mortality rate of stomach cancer has been declining more rapidly than it has among Japanese. The factors involved in the Korean-Japanese difference of liver cancer and those involved in the rapid decrease of stomach cancer among Koreans in Japan are discussed.