The empirical literature focusing mainly on the USA suggests that class absenteeism undermines students' academic performance and that an enforced mandatory attendance policy may be beneficial. Based on a different cultural and economic context, and using data on 146 second-year management students enrolled in a macroeconomics course at an elite economics school in Portugal, it is shown that even when controlling for potential endogenous factors associated with attendance and academic performance, absenteeism considerably lowers the students' final grade (about 2 points in a 0-20-point grading scheme). In addition, it is established that a compulsory, though flexible, attendance policy contributes to improving students' academic performance.