The acquisition of the digestive system concepts is still problematic. In this study, we assessed whether 3rd year secondary school learners have acquired and assimilated these concepts at the end of the module. The results we obtained showed that young learners have problems in acquiring these concepts to varying degrees. The role of aliments, the organs and functions of the digestive system, and the phenomena of digestion were relatively acquired by the students. However, the dangers threatening the digestive system and the means of prevention remained unknown for the great majority of these learners. We have also found that learners confused with the digestive system and the respiratory system in some representations.