The professional education of nontraditional adult teacher candidates requires learning environments that include multiple perspectives, democratic principles, sound pedagogy, and critical thinking. Facilitating adult learning is a very complex process that incorporates diverse paradigms of thought (Galbraith, 1991, p. ix). The process requires a metacognitive understanding of varying worldviews, shifting expectations, diverse learning styles, personalities, levels of sophistication, and various cultural and ethical backgrounds. Different approaches are often necessary with adult learners because of their diversity, variability, varying intellectual levels, and extensive past experiences. Teacher educators should recognize and value the life influences on the personal and professional development of nontraditional teacher candidates because these can be used to advance their growth. Institutional settings and the social and political climate for learning must accommodate to the educational encounter between teacher educator and adult learner. Adult learners come to teacher preparation programs with a clear set of goals and sense of themselves that their cumulative life experiences have shaped. In this article, we compare the professional beliefs and teaching behaviors of traditional and nontraditional adult teacher candidates. Using weekly student autobiographical critical reflections during student teaching, we built trust and established authentic needs and purposes for coaching novice teachers in their professional development. In this study, nontraditional adult teacher candidates are preservice teachers over 25 years old with varied life experiences, including participation in the workforce, child rearing, military service, or postsecondary training. These experiences provide adult beginning teachers with skills and competencies transferable to becoming a teacher. Nontraditional adult teacher candidates' beliefs and operational theories may be more ingrained than those of traditional candidates who lack maturation, knowledge, and life experiences. The social, political, and cultural context influences how teacher candidates view themselves, their work, and the world. Marsick and Watkins (1991) state, The teacher's use of learning methods is highly colored by the lens through which they view themselves, their work, and the world (p. 75). The worldviews of nontraditional adult teacher candidates embody basic beliefs and assumptions about the human condition reflected in the paradigms they select for teaching and learning. These beliefs and assumptions form the basis for the operational theories they implement in classrooms. Nontraditional adult teacher candidates may need strategies to help them become conscious of the consequences of their attitudes, values, beliefs, and rules, long taken for granted, by which they make sense of their world. They may also need structures that facilitate questioning whether their traditional ways of doing things produce the results they want to achieve in their teaching. In this article, we describe major characteristics of the professional development of a sample of traditional and nontraditional adult teacher candidates during student teaching. We used critical reflection as a teaching, metacognitive tool to facilitate their ability to understand how one acquires professional knowledge, develops teaching practice, and becomes a teacher. We wanted to expedite their comprehension of the relationship between teachers' beliefs about teaching and learning and their pedagogical decisions. We used critical reflection as a data collection tool to help student teaching supervisors study the professional growth and development of beginning teachers and compare the traditional and nontraditional adult teacher candidates. Thus, we identified and documented the underlying assumptions, focus issues, and self-evaluation dynamics of becoming a critically reflective beginning teacher and how these affect professional development for two groups. …