The incidences of symptomatic coeliac disease (CD) and pyloric stenosis (PS) in children born 1960-1979 were studied retrospectively in Northern Finland. The total incidence of CD was 42.3, and of PS 122.7 per 100,000 live births. The figure for CD was lower than in studies from other industrial countries during the same period. The incidence of CD was highest in the early 1970s, and has decreased significantly, at least in children under two years of age, during the late 1970s. In the city of Oulu the incidence of CD was significantly higher than that in the surrounding countryside. Active search, with small intestinal biopsies, should reveal over 90% of cases with CD before the age of two years. Of 78 children diagnosed as having CD during the observation period, 75% were breast-fed for less than three months, 18% had signs of allergy at the time of diagnosis and seven % had IgA deficiency. In four patients CD was associated with diabetes. The incidence of PS varied from 107 per 100,000 live births in the early 1960S to 153 per 100,000 in the late 1960s. No significant seasonal variance was observed in the analysis of 226 children with PS in the study.