Purpose: The present study was carried out to analyze the functional content of primary school mathematics textbooks for mentally retarded students.Methodology: After extracting the conceptual pattern and constructing the checklists based on the aforementioned pattern, in the first phase of the study, the functional content of the textbooks was investigated. The 9 components of the patterns are: mathematical vocabulary, numbers, counting, numerical operations, geometrical shapes, measurement, time, money and shopping, and mathematics-related instruments. The content analysis or in other words constructing the checklists was achieved by two assessors.Findings: The results of the analysis point out there was no difference between the opinions of the two assessors in four of the textbooks and for the remaining three textbooks, the difference was insignificant. Subcategories of functional mathematics which have been presented in none of the textbooks are as following: some mathematical concepts such as direction and distance, ordinal numbers, unit of temperature in the category of measurement, time of day, some common coins and bills, vending machine and ATM in the category of money and shopping, identifying geometrical shapes in objects and natural sceneries, and also related instruments such as digital watch, telephone, calculator, thermometer, and scale. Furthermore, many issues have been superficially dealt with.Conclusion: The obtained results imply that in developing the mathematics textbooks for this group of students, the appropriateness of the content to the readers’ needs (the functional aspect) was not fully taken into consideration and the existing content requires much alteration and a number of additional issues and concepts.