Debate continues about the relationship between schools divided on ethno-religious lines and their implications for social cohesion. One argument against the existence of separate schools is that they limit opportunities for children from different groups to engage with each other, promoting intergroup suspicion and sectarianism. Using intergroup contact theory we examine the impact on outgroup attitudes of pupils attending mixed and separate post-primary schools in Northern Ireland. Data were collected through a survey of more than 3,500 pupils and analyses show that, irrespective of school type, intergroup contact at school is strongly associated with more positive orientations to the ethno-religious outgroup. The policy implications of these findings are discussed.