The Outgroup Prejudice Index is a six-item scale that uses social distance to assess prejudice towards ethnic and religious out groups among Asians and whites. It was developed among a sample of 2,982 teenagers attending schools in northern England who indicated their religion as "Muslim", "Christian" or "No religion". The scale demonstrated internal consistency reliability among both Asian (Cronbach's alpha = 0.78) and white (Cronbach's alpha = 0.85) pupils. The scale demonstrated construct validity in two ways: scores were correlated with a second scale based on stereotyped attitudes, and were also lower among those with friends in outgroups, suggesting the index was a valid measure of ethnic or religious outgroup prejudice. (Contains 6 tables.)