In 1956, a study of the iodine metabolism in endemic goitre was made on a group of inhabitants of the Aland Islands, an autonomous province of Finland. The number of Alanders studied was 130. In a follow-up study 25 years later, 101 still living subjects from the original study could be traced. 17 of them had become hyperthyroid, 7 had been operated on for non-toxic goitre, and 4 had become hypothyroid. There was no correlation between thyroid hormone excretion values in 1956 and subsequent hyperthyroidism. Rheumatoid arthritis was overrepresented in the goitre group compared with the group without goitres, as well as compared with statistical figures on the frequency of rheumatic disease among the population in general of Aland and of Finland as a whole.