The paper reports on the results of a study aiming to analyze the teachers’ perception of their professionalism in teaching English as non-English education graduates as well as the challenges that are faced by the teachers. The data were collected from observation and interview with two English teachers of the Senior High School in Subang, West Java, Indonesia. The data were analyzed by a qualitative method through three steps: reduction, display and conclusion. From the interview result, two teachers have similar perceptions of professionalism in teaching. They believed that professional development can be improved by joining some events and programs in an effort of developing their pedagogical competence such as seminars, workshops, short courses or teacher training related to teaching in order to develop their knowledge of teaching methods. Meanwhile, the observation results show that both teachers have not applied all practical professional development activities in their classrooms, such as the implementation of lesson study is not achieved well and the teachers are not familiar with self-reflection. The result highlighted from two teachers’ perceptions of being professional that they are consciously confident that professionalism is undeniable for the sake of students’ achievement in learning English by having various of professional development courses or trainings. In conclusion, the researcher assumed that their teaching English professionalism could be developed as long as they have taught English skills which can be reinforced by some experiences in teaching English, applying pedagogical knowledge and attending teacher’s programs that can improve their competence in teaching.