This study investigated student teachers' views on their best and worst teachers' characteristics. Students in four sections of a sophomore-level teacher education program prerequisite course were required to write half-page descriptions of their best and worst teachers from elementary and high school, focusing on the behaviors and attitudes that made these teachers the best or worst. These descriptions were coded for six themes of teacher effectiveness: student centeredness, enthusiasm for teaching, ethicalness, classroom and behavior management, teaching methodology, and knowledge of subject. Data analysis indicated that the predominant theme in descriptions of good teachers was student-centeredness, followed by teaching methodology. The same two major themes were present (at a lower rate and in reverse order) in descriptions of the worst teachers. Students' views differed by gender in regard to teaching methodology and ethical behavior. (Contains 14 references and 3 tables.) (SM)