This article reports the findings of research into how Latin-American principals distribute the time they devote to the performance of their functions, what characteristics of principals and schools affect principals' time distribution and how a principal's distribution of time influences the performance of the students at the principal's school. UNESCO's SERCE (Second Regional Comparative and Explanatory Study) database was mined for information about 2,580 principals from 16 Latin-American countries. Data indicate that just 57.7% of school principals in the region are occupied full-time by their school job, and on average they spend 80% of their school time on managerial work and the other 20% on classroom teaching. Of the time allocation directly related to management, principals spend an average of 25% on administrative tasks, 16% on activities related with instructive leadership and 16% on tasks pertaining to supervising and advising the teaching staff (although this varies widely among countries). It was also found that the principal's age, the school's size and the situation of the zone where the school is located are factors that influence time distribution. Lastly, the percentage of time principals spend on educational leadership tasks has a positive influence on the performance of the school's students. School management policies in Latin America should be reformulated to free principals from administrative tasks in order to enable them to devote themselves to activities related with educational leadership.