This study examines the listening and speaking activities of ELT textbooks adopted in Iranian junior and senior high schools, namely the Prospect and Vision series, with reference to English as a lingua franca (ELF) features. To do so, the researchers analysed the textbooks' activities against ELF criteria adopted from Caleffi's study (2016). The results of the critical content analysis revealed that the textbooks do not provide sufficient exposure to a variety of situational contexts, characters, and cultural elements, and do not provide sufficient opportunities for English teachers to implement the socio-linguistic and socio-cultural realities of the English language in their English classes. This seems to have resulted in unrealistic and unauthentic presentations of English in the textbook series. The findings can encourage national and international ELT textbook designers to eschew a fixed and monolithic approach to the English language and make more extensive use of ELF-informed materials in ELT textbooks.