Of particular importance for education policy-makers is the possibility that teacher mobility adversely affects the quality of teaching in schools serving mainly disadvantaged and minority children. This paper examines the main drivers of the mobility of Italian teachers by using applications-to-transfer data. We find that teachers systematically try to move away from schools where teaching is likely to be more difficult because of the student mix or the social context of the school. Given the absence of any criteria other than seniority in regulating teachers' allocation across schools, disadvantaged students frequently end up with less experienced teachers who are often just waiting to move elsewhere. (Contains 6 tables and 5 figures.)