Cognitive linguistics rejects the traditional view of metaphor as merely a linguistic feature, a tool of poetic imagination, or a rhetorical ornament, and instead regards metaphor as a means of conceptualization, whereby one idea or conceptual domain is understood in terms of another. After outlining conceptual metaphor from the perspective of cognitive semantics, this study examined the types of metaphors present in Persian textbooks at the first secondary level. The aim was to determine, based on Lakoff and Johnson’s classification, which metaphors are employed, which occur most frequently, and how these metaphors function in facilitating comprehension of textual concepts, as well as to assess the extent to which their potential has been utilized in teaching. The results show that ontological metaphor has the highest frequency (71%), while directional metaphor accounts for 7% and structural metaphor for 22%. All types of metaphor played a significant role in visualizing and understanding abstract concepts. Given the considerable capacity of conceptual metaphors to render abstractions more accessible, Persian textbooks could benefit from the inclusion of selected texts from classical Persian literature—rich in conceptual metaphors—for the teaching of cultural themes and the moral education of students.