Effective teaching of English for Occupational Purposes (EOP) is considered to enhance workers' performance, efficacy, and professional development. Thus, what students and teachers believe to lead to effective EOP teaching is worth exploring. This study set out to compare students' and teachers' beliefs about effective EOP teaching. It employed a sequential mixed-methods design with a questionnaire initially administered to 306 voluntary participants, including 108 teachers and 198 sophomore and junior students who participated in teaching and learning EOP. Subsequently, semi-structured interviews with 30 voluntary participants selected from the first stage sample were conducted. The findings showed that students and teachers generally indicated their high agreement with communicative language teaching strategies in EOP. However, discrepancies were found in most observed factors of EOP teaching, including language skills, communicative language teaching, content and language integrated learning, and assessment, except technology integration. From the findings, it is suggested that both EOP students and teachers should be informed of what constitutes effective EOP teaching.