Guided by the analytical framework in the current literature, whereby ten nature of science (NOS) aspects were targeted, this study aims at assessing the extent to which the three physics textbooks for Cycle 4 of Fundamental Schools in Burundi represent the NOS aspects. The quantitative embedded research design which combines the qualitative and quantitative to both the representations of text and images were applied to collect and analyses data. Three physics textbooks used in this study as textbooks I, II and III (grade 7 textbook, grade 8 textbook and grade 9 textbook) were purposively selected. 65 physics lessons were analyzed in three steps including exploring representations of NOS aspects, representations of NOS teaching approaches and accuracy and completeness of NOS aspects. Data were collected using a guide document analysis and a rubric of NOS scoring and were analysed descriptively. The findings found a considerable deficit of NOS aspects in the physics textbooks. The findings also revealed the critical situation where the few lessons poorly represent the NOS aspects and the majority of them do not include the aspects of NOS. Furthermore, this study suggests the in-charge of quality assurance to evaluate and deliberate on the accuracy and completeness of physics textbooks for Cycle 4 of Fundamental Education in Burundi.