Purpose: The purpose of this paper is to provide insight into the current contributions of private schools to education provision in Tanzania, and to consider the feasibility of a school voucher program to contribute to the expansion of the secondary school system, compared to the alternative expansion of public secondary education. Design/methodology/approach: The study offers an analysis of current educational circumstances and educational goals in Tanzania, and projects differential costs and outcomes associated with various options for expanding secondary education. Data come from two sources: a census of the private schooling market in the Morogoro Urban district, conducted as part of the World Bank's Systems Approach for Better Education Results initiative; and Tanzania's National Panel Survey 2010-2011. Findings: For those students unable to cover the full cost of secondary education, findings suggest that a targeted private school voucher would be an efficient and equitable policy mechanism for secondary school expansion. Such an approach would ease the financial burden on government for constructing all new schools, yet assure access for the most vulnerable. Originality/value: The implementation of school voucher programs is increasing in low-income countries. It is important for policy makers to carefully consider the appropriateness of this type of policy intervention for their particular educational contexts. This paper models an approach by which researchers and policymakers can assess the educational circumstances of a particular location, and determine the potential effectiveness of a private school voucher policy.