Decision-making and pedagogical reasoning constitute the foundation of teacher professional practice. This qualitative study was conducted to explore novice Iranian EFL teachers’ professional decision-making and pedagogical reasoning in the three domains of (1) planning and preparation, (2) classroom management, and (3) professional responsibilities during the three phases of pre-active, interactive, and post-active teaching. Data from two sources including scenarios and audio journals revealed five novice teachers’ decisions in each domain and their relevant reasoning. Decisions in the first domain were discovered to embody teachers’ choices about materials, teaching methods, and assessment. In the second domain, teachers’ decisions were focused on management, flexibility, and accountability. In the third domain, their decisions were aimed at professional interaction and professional development. Moreover, a new decision domain, ‘dispositions’, was discovered, which comprised novice teachers’ choice of ethical conduct, care, and accountability. This led to the introduction of a new phase of teaching, beyond-active, which greatly influenced all other decision domains and teaching phases. Additionally, novice teachers’ pedagogical reasoning was uncovered to stem from their knowledge, skills, and personality attributes. These findings suggest that knowledge about teachers’ decisions and underlying reasoning provides insights into the scope of their professional knowledge and practice.