This paper investigates the causal impact of the Syria crisis on education quality in Jordan, in particular, the consequences of overcrowding and ‘double-shifting’ in public schools. The analysis is based on data collected from a sample of Jordanian public schools in Qasabet-Irbid district in Northern Jordan, close to the Syrian border. The authors carried out a set of double differences (pre-and-post crisis comparisons of students’ scores in a group of affected schools with respect to a control group of unaffected schools) to determine the causal impact of the crisis on education quality in the affected schools. They find an overall negative impact of Syrian refugee enrollment due to both overcrowding and double-shift practices. The performance of students in affected schools deteriorated as measured by scores in four main subjects (Math, Science, Arabic, and English), relative to the counterfactual sample, particularly in Math and Science. This negative impact is confirmed by qualitative analysis.