Multiple school jobs are more common in developing countries and among teachers who teach specific subject areas. This paper examines whether student achievement is affected when teachers work in more than one school. We use longitudinal data from Rio de Janeiro and exploit within teacher-school-grade variation in the number of school jobs over time. We found that an increase in the number of school jobs leads to a decrease in student achievement. Our results suggest that multiple school jobs are more detrimental for female teachers, probably because women take on more responsibilities outside of work. We also found that the negative impact of multiple school jobs is particularly larger for poorer students who participate in conditional cash transfer programs. Lastly, our results show that an increase in the number of school jobs is associated with an increase in teachers’ workload as measured by the number of teaching hours and the number of unique subject-areas, grade-levels, and students taught.