To meet the ever-changing needs of students in the modern world, forward-thinking educators are crossing the traditional borders of their own disciplines to work with colleagues from other fields to develop novel approaches to teaching. Examples of cross-disciplinary efforts illustrate both the creativity of their participants and the promise and excitement that they hold for students: Biochemists are working with business faculty (Keller and Cox 2004), philosophy teachers are collaborating with physicists (Jordan 1989), and mathematics instructors are teaming up with music teachers (Bamberger 2000). Similarly, English language teaching (ELT) professionals are reaching out to colleagues from other disciplines (including health, history, humanities, math, psychology, science, social studies, and sociology) at primary, secondary, and tertiary levels to develop innovative courses, materials, and instructional approaches. This article shares insights gained from the authors' interdisciplinary work in the hopes that other ELT professionals might benefit from them. The authors discuss specific steps that can be taken to ensure successful partnerships as they focus on three key areas: (1) initiating an interdisciplinary project; (2) establishing an interdisciplinary team; and (3) working successfully with other disciplines. The discussion is organized around nine ELT scenarios and numerous English idioms that illustrate many issues that could arise in the course of interdisciplinary collaboration.