When given the opportunity, many teachers choose to leave schools serving poor, low-performing, and minority students. While substantial research has documented this phenomenon, far less effort has gone into understanding what features of the working conditions in these schools drive this relatively high turnover rate. This paper explores the relationship between school contextual factors and teacher retention decisions in New York City. The methodological approach separates the effects of teacher characteristics from school characteristics by modeling the relationship between the assessments of school contextual factors by one set of teachers and the turnover decisions by other teachers within the same school. Teachers perceptions of the school administration have by far the greatest influence on teacher-retention decisions. This effect of administration is consistent for first-year teachers and the full sample of teachers and is confirmed by a survey of teachers who have recently left teaching in New York City.