The knowledge level of the principles of nutrition was assessed in population of 6411 schoolchildren from 215 schools chosen at random from the whole territory of Poland. In this population 2644 (41%) children attended elementary schools, 1315 (21%) attended general education secondary schools, 1163 (18%) were in technical gastronomy schools and 1289 (20%) were in vocational gastronomy schools. For data gathering the inquiry method was applied using a test with 60 questions identical for all questioned pupils. The knowledge level of the bases of nutrition measured by the average number of correct responses was higher in secondary schools than in elementary schools, with the highest number of correct responses in technical gastronomy schools, while in general education secondary schools this level was similar to that in vocational gastronomy schools. In elementary schools and general education secondary schools this knowledge was significantly higher among girls than boys. The knowledge of the principles of correct composition of meals and the technology of meal preparation and food storage was particularly low among all pupils.