As patient care has matured and become increasingly complex, the fundamental skill set for the modern radiation oncologist has evolved as well. The initial generation of radiation oncologists trained in the United States and North America were taught by highly skilled mentors with expertise in surface anatomy and fluoroscopy with radiation fields designed by common understanding of the pattern of disease spread. Our first-generation mentors were critical thought leaders in applying management tools available at that time to trainees. This generation of radiation oncologists applied their expertise with the tools of the day; however, as our technology has evolved, the modern radiation oncologist requires skills commensurate with rapid technology changes. As we evolve and mature as thought leaders in the oncology practice of today, the skills required for the modern radiation oncologist both in clinical care and in basic science evolve and reach a new level of performance to match expectations of our colleagues and patients.