The deaths caused by the mentioned four basic cancer sites of the gastrointestinal tract represented almost one third of all deaths from cancer in Slovakia during the decade 1968--1977. The age-adjusted rates and trends showed substantial increase of the mortality from colon cancer in both sexes as well as from rectum and oesophagus cancer in men and simultaneously significant decrease of stomach cancer in men and women together with quite unchanged rates of rectum and oesophagus cancer mortality in women during the investigated period. Study of the geographic distribution of standardised mortality rates of these cancer sites revealed the existence of great differences in the frame of the individual sites as well as the tendency of substitute the decreasing mortality rates of stomach cancer with those of colon and rectum especially in the western part of the country. The possible advantages and perspectives of the investigation of the geographic patterns of cancer mortality in adequately great territorial units in this country are discussed.