New education has emphasized the importance of developing learner autonomy (LA). The concept was first defined by Holec (1981) as learners' ability to take control and responsibility of his own learning. Learner autonomy enables learners to sustain long-life learning skills. In Omani secondary schools, learner autonomy has been a desirable goal in teaching English as a foreign language with the mission to enhance active learning, independent learning strategies and independent thinking skills. However, few studies have been conducted on the practice of learner autonomy in Omani secondary schools. This study intended to explore EFL teachers' perceptions of learner autonomy, their actual practices and the challenges and factors affecting promoting learner autonomy at secondary schools in Oman. In addition, it attempted to explore if there is any association between teachers' general beliefs about promoting LA and their academic level, gender and years of experience. The data collection instruments included a teachers' perceptions questionnaire, classroom observation data, and interview with teachers. Ordinal regression analysis and grounded theory were used to analyze the quantitative and qualitative data, respectively. The results revealed that although EFL teachers at Omani secondary schools practice some strategies that promote learner autonomy, these practices are not aimed to promote LA. Moreover, the study results showed some discrepancies between teachers' beliefs about promoting learner autonomy and their actual practices due to some constraints and challenges that affect this process. These challenges involve the intensive English curriculum, teachers being overloaded with numerous school tasks besides teaching, learners' limited exposure to English outside classroom and teachers' professional background in the concept of learner autonomy, its principles and practices. In the current study, no significant association was found between teachers' general beliefs of LA and their particulars.