A four-month participant-observation study of new teaching assistants examined what happens when "teaching stories" are taken from the margins and placed at the center of a teacher preparation program. New teaching assistants participated in a week-long presemester orientation, took a one-semester Theory and Practice seminar, and enrolled in a one-credit practicum. During the orientation, experienced teachers modeled and told stories about their own classroom practice. Teaching assistants kept weekly journals of their teaching experiences and met once a week with a faculty member to tell stories about what was happening in their classrooms. Results indicated that teaching assistants struggled with at least three problems: (1) some were skeptical about the validity and reliability of the local knowledge represented by stories; (2) some became cynical because they perceived that certain kinds of stories were being endorsed over others; and (3) some worried that they lacked control of the meanings and uses of their stories. Two reasons emerged as to why stress and ambivalence remained over the use of such stories even when they were authorized within a program: teaching assistants may have been confused about whether they were subjects or objects of their own stories, and about what counts as disciplinary knowledge. Findings suggest that authorizing stories in a teacher preparation program introduces difficult new issues of authority and credibility. (RS)