Public Debt Management in transition and other emerging countries is more complex and crucial than in the developed ones. In these economies, the choice of the financial structure of the public debt is key to warrant fiscal stability because of the higher volatility of macroeconomic and financial conditions. In addition, public debt dynamics exacerbate the weight of fiscal risk as a source of macroeconomic instability. This work is focussed on the optimal Public Debt Management in the Former Soviet Union countries. The book presents a brief description of the economy and public debt structure of the Former Soviet Union countries since their independence and the optimal debt structure of the Republic of Armenia and the Republic of Lithuania.