Science course includes very different concrete and abstract concepts. For this reason, teaching materials that can have a positive effect on students in both cognitive and affective fields are used in the education process. In this context, textbooks are one of the most preferred teaching materials. Textbooks are teaching materials used in the planned transfer of the subjects in the curriculum and in teaching the concepts to the students. For this reason, the textbooks should be free from erroneous information. In this research, it is aimed to examine three different sources, which were accepted as Secondary School and Imam Hatip Secondary School 6th Grade Science Textbooks for five years by the Ministry of National Education, in terms of scientific content and learning outcomes. Within the scope of the research, the units "Systems in Our Body" and "Systems in Our Body and Its Health" in the textbooks were focused. The data were analyzed using the document analysis method. International books were taken as reference in order to determine the scientific accuracy of the information in the units. As a result of the research; It has been determined that there are scientific mistakes and conceptual confusions that will cause misconceptions in students about tissues, joints, muscles, bones, digestion and absorption of nutrients, digestive system, circulatory system, blood structure, excretory system, nervous system, respiratory system and sensory organs. It has been concluded that there are scientific mistakes in the unit evaluation questions and mistakes in terms of measurement and evaluation. In terms of outcomes, it was observed that the textbooks were incompatible with each other and the curriculum. It can be said that correcting the mistakes in the textbooks and preparing them in accordance with the achievements are important for the future of the education process.