The objective of this retrospective study was to see whether there was an increasing incidence of adenocarcinoma of the oesophagus and gastric cardia in the Swedish population 1970-1997. If there was, could it be explained as a period or cohort phenomenon? The data were compared with the incidence of squamous cell carcinoma and gastric adenocarcinoma with the gastric cardia excluded. Age standardised incidence for each sex was calculated using the age distribution of the world population as a reference. For the combined group of adenocarcinoma in the oesophagus and gastric cardia incidence gradually increased during the study period. The median increase between adjacent five-year intervals was 14% in men and 20% in women. Previously described risk factors are gastro-oesophageal reflux, obesity and smoking. This study suggests that the increasing incidence also can be explained as a shift in classification from squamous cell carcinoma to adenocarcinoma after 1985.