There is speculation about madaris in Pakistan as sources of terrorists and about levels and reasons for enrolment, but a dearth of empirical data. We studied madarsah enrolment among 53,960 representative households; 853 focus groups of parents discussed enrolment choices. In 2004, 2.6% of all children (3.8% of school-going children) aged 5-9 years attended a madarsah. Children from urban and less educated households were more likely to attend a madarsah, but there was no difference by sex of the child or household vulnerability. Parents chose madaris because they offered an Islamic education. Our findings challenge misconceptions about madaris in Pakistan. (Contains 2 figures and 1 table.)