Traditional ways of teaching were challenged by differentiated instruction which aims to embrace students' variance. Teachers are expected to maximize the learning opportunities by meeting the diverse needs of their learners. English teachers in Omani schools are trained and instructed to modify the content to meet students' different levels; however, teachers in higher education institutions are given more freedom in planning and conducting their classes. This research investigated teachers' perceptions of differentiated instruction which is customised to meet the diversity of learning needs and interests of English as foreign language students in the University of Technology and Applied Sciences-Rustaq (UTAS-Rustaq). The study also sought to identify practices teachers follow to implement differentiated instruction. An exploratory, descriptive analysis and a survey were employed to obtain the necessary data, which indicated that teachers are aware of differentiating instruction and the related practices. Teachers also showed a good understanding of the type of knowledge needed to obtain before implementing differentiation and the assessment tools to attain them. However, the results also indicate an essential need for structural support, professional development, to meet the challenges identified by teachers to maintain the continuity of these practices.