This paper examines policies to tax international private capital flows and securities transactions in developing countries. Many recent studies focus on the macroeconomic dividends associated with these policies (namely, their contribution to macroeconomic and financial stability and lengthened investor time horizons). In this paper I explore whether the potential of these policies to raise much-needed tax revenues in developing countries augments their well-known macroeconomic benefits. To my knowledge, there has been no effort to examine systematically the public finance issues related to the taxation of international private capital flows or securities transactions in the developing country context. I conclude that the public finance implications of these policies in middle-income developing countries offers additional support to the macroeconomic case for them. To different degrees, taxation of international private capital flows and securities transactions has the potential to raise modest revenues in middle-income countries. However, far more important is the potential of these policies to offer valuable macroeconomic dividends on the national level. These national macroeconomic dividends have the potential to bear fruit globally. This is because experiences with financial contagion over the last decade suggest that global financial stability can be enhanced via the promotion of domestic financial stability in developing countries.