Data on the body mass index (BMI) from four Scandinavian countries are compared. The Finnish values are markedly higher than those of the other countries. This holds for both sexes. Among these the Norwegians deviate by showing higher values for females, though not reaching the Finnish level, but lower values for the males. The populations from which the observations are drawn are differently sampled. There is no evidence that differences as to composition in rural/urban populations can explain the differences.