 The study assessed the validity of an age-specific food picture book, which contains commonly eaten foods among Finnish children, for parents and early educators in estimating food portion sizes. The results showed that the food picture book was a useful aid for the estimation of food portion sizes. Parents and early educators evaluated the portion sizes with similar accuracy. This article was authored by Kai Janissanen, Lisa Kaukalo, Henna Vepsilainen, and others.