Cancer incidence rates were examined in the native peoples of the far north-east of Siberia for the years 1977-1988. Particularly high rates of cancers of the stomach, lung, oesophagus and cervix were observed. For stomach cancer, the male and female age-standardized (to the world population) rates were 103.9 per 100,000 and 50.0 per 100,000 respectively. The corresponding lung cancer rates were 109.4 and 45.7, and for oesophageal cancer 83.9 and 35.0. The age-standardized cervical cancer rate was 38.5 per 100,000. Rates of these cancers were considerably higher than in native Alaskan peoples, although the latter had higher rates of breast and colorectal cancers. The rates were also much higher than those of the migrant peoples from Russia and elsewhere who have settled in the far north-east over the past 3 centuries, particularly at younger ages. Male rates of stomach and lung cancer were highest in the paleo-Asiatic peoples of the north, whereas male oesophageal rates were highest in the Taiga people. In females, rates of stomach and oesophageal cancers were highest in the paleo-Asiatic peoples, and rates of lung cancer were highest in the Taiga nationalities. Cervical cancer rates were highest in the Amuro-Sakhalin nationalities of the south. Further research is needed at individual levels to explain the very high risks and the differences among the ethnic groups.