This study was designed to examine the effect of Swedish Knife Model on students' understanding of digestive system. A simple experimental design (pretest-treatment-posttest) was used in the study and internal comparison of the results of the one group was made. The sample consisted of 40 7th grade Turkish students whose ages range from 13 to 15. The Digestion Test, comprising 7 open-ended questions and a semi structured interview were used to collect the data. The pretest results showed that the students had misconceptions about the chemical and mechanical digestion and also the functions of the digestive organs. The total results of pre and post-test comparison also revealed that Swedish Knife Model consisting of discussion, puzzle, analogy development, grid, story completion and cut and stick activities helped the students to overcome their alternative conceptions about digestion, function and location of the digestive organs. (Contains 7 tables.)