Based on the geographical distribution and changes over time in the mortality of certain cancer sites of the digestive system (oral cavity, pharynx, esophagus, stomach, large intestine and liver) in Croatia, the diet is assumed to be a major causative factor. On analysis, geographical maps of cumulative mortality rates from age groups 0-64 and 0-74 years in the periods 1978-80 and 1988-9 showed stomachal cancer load to be heavier in northern than southern Croatia. Colorectal cancer load has an even distribution except in the Licka and Zadarska areas. The mortality of esophagus cancer is higher in the areas of Hrvatskozagorska, Varazdinska, Osjecha, Slavonskobrodska and Istria. While compared with other European countries, oral cavity cancer mortality in Croatia is similar to theirs, our stomachal cancer mortality is higher than of any southern neighbour. Croatia's stomachal cancer mortality rates closely resemble Hungary's and Poland's, those of colorectal cancer being similar to Italy's. Our liver cancer mortality is lower than the Italian and Greek. Other epidemiological investigations have also shown Croatia's north to carry a greater load not only of cancer, but also of chronic diseases. Diet can be hypothesized to be one of the major factors thereby.