In a total number of approximately 500 school-children, belonging to a suburban area around Pordenone (Northern Italy), aged 6-9-12-15, we have performed a two years follow-up on serum TC and TG. As for serum TC, a progressive decrease of mean TC levels at the two rescreenings was observed. We cannot explain such trend, unless we admit that some dietary modification has been introduced in the families, although no dietary advices were given. However the observed decrease of the TC levels, makes clear that a single serum TC determination is not sufficient in order to define the lipid profile of a given subject. Unlike TC, serum TG tend to increase with the age. The "longitudinal" behavior of TC and TG is similar for both males and females.