Biased textbooks can have a negative impact on students and may lead to the construction of gender stereotypes. This is why researchers have analyzed gender bias in various textbooks at different levels. Teachers' perceptions about gender bias, however, have rarely been explored in Pakistan, even in the case of female teachers. Based on this gap, the present study analyzed the perceptions of female teachers regarding gender bias in English textbooks at secondary-school level in Khyber Pakhtunkhwa, Pakistan. Questionnaires and interviews were used to collect data, which were analyzed both quantitatively and qualitatively. Findings revealed that teachers are not aware of the adverse effects of gender bias in textbooks and therefore could not suggest any strategies to address it, though they considered English textbooks more biased in terms of dominant male characters than in language. The respondents, however, agreed that the textbooks need revision for both content and language. The study adds to the existing literature on the presence of gender discrimination in textbooks. Its findings are all the more significant in that they highlight teachers' lack of awareness regarding gender bias in the textbooks and its effect on the learners.