Powerful presidents are generally thought to be detrimental to the overall development of democracy. However, conditions for a reduction of presidential power have thus far not been systematically investigated in political science research. The present study traces institutional reform processes in four post-socialist countries (Armenia, Croatia, Russia, Ukraine) and compares them with regard to similarities and differences. The empirical case studies show that reforms were generally aimed at promoting the self-interest of the president. However, the study also indicates that institutional hurdles as well as veto players such as constitutional courts and external actors have proven to play a significant role in reform processes.