Build-operate-transfer (BOT) contracts have been recognized in Iran as an attractive mechanism by which private sector investment can be mobilized into economic sectors remaining in the public domain. A variety of projects from different sectors, such as telecommunication, power, water and transport, are either under consideration, tendering or negotiation to be awarded on a BOT basis. This article considers the rules and principles that inspire the legal framework for BOT projects in Iran. To this end, the legal requirements and support provided by different laws and regulations will be investigated. The adequacy and efficiency of this legal framework in enabling potential investors to estimate the costs and risk of their investment in BOT projects will then be discussed.