Moral reasoning is a key element of the Singapore Ministry of Education's Character and Citizenship Education curriculum, and educators in Singapore are currently encouraged to facilitate growth in students' moral reasoning based on the Stages of Moral Development established by Lawrence Kohlberg. To monitor students' progress in this area, however, a validated test of moral reasoning is needed. A review of existing moral reasoning assessments indicated that none provide a practical means by which large numbers of students in Singapore classrooms can be assessed in this area. In this study, the Moral Reasoning Questionnaire (MRQ) was developed and validated to assess moral reasoning development in Singapore secondary classrooms. The MRQ presents moral dilemmas that integrate prosocial, anti-social, and social pressure elements within situations that would be familiar to Singapore secondary (grades 7-12, aged between 12 and 18) students. Evidence supported the reliability and validity of the MRQ. The MRQ could be applicable as a practical means to assess moral reasoning on a broad-scale basis.