The proliferation of urban rail transit public-private partnerships (PPPs) in Latin America and Southeast Asia is a recent phenomenon. This paper first reviews the theoretical literature on the public procurement versus PPP decision in the context of rail transit and assesses the risks involved in entering these partnerships. The urban rail transit PPP approaches adopted in Bangkok, Kuala Lumpur, Buenos Aires, Rio de Janeiro, Singapore, Hong Kong, and London are described and classified into four broad approaches: (i) the development of new systems through Design-Build-Finance-Operate (DBFO), (ii) the concessioning of rail and subway services, (iii) the sale of state-owned operators through share issue privatization, and (iv) PPPs for infrastructure maintenance and upgrading. The different risk allocation strategies adopted under each of the above approach are analyzed for the extent to which they correspond to the theoretical recommendations. The concluding section provides a summary of the trade-offs that policy makers make when deciding between alternative strategies.