In many countries, primary school enrolment is still not universal. More than 20 per cent of children do not attend school in many countries in sub-Saharan Africa, and around of a third of those who do enrol drop out before completing sixth grade. Secondary school enrolments are far lower. In many countries, fewer than half of all children attend secondary school. And the quality of education is low, with many students having low literacy and maths skills after several years of schooling. Cash transfer programmes, targeted at poor families, have become a popular means of tackling low enrolment. Conditional cash transfers (CCTs) for schooling are provided to poor households provided that children of school age enrol and attend school. Unconditional cash transfers (UCTs) are provided without conditions. This Campbell systematic review assesses the effects of conditional and unconditional cash transfer programmes on education outcomes in low- and middle-income countries. The review summarizes findings from 35 studies.