This paper addresses two questions: 1) How to promote demand for male circumcision in the context of secondary schools in Malawi and 2) What is the role of peer effects in the demand for male circumcision. We randomly provided free male circumcision and transportation vouchers to male students across 33 public secondary schools near Lilongwe, Malawi. Using a two-step randomized design, we first assigned classrooms into three groups (100% Treatment, 50% Treatment, or No Treatment classrooms) and then also randomly selected half of male students in 50% Treatment classrooms for treatment. We find that our intervention substantially increased the demand for male circumcision by on average 15.4 percentage points (188%). We also find evidence of peer effects since untreated students in 50% Treatment classrooms were 3.8 percentage points (79%) more likely to get circumcised than students in No Treatment classrooms. Finally, we provide evidence of important reinforcement effects when close friends within the same classroom receive the intervention together. (JEL: C93, D1, I12)