This edited collection examines the politics of semi-presidential countries in the Caucasus and Central Asia. Semi-presidentialism is the situation where there is both a directly elected fixed-term president and a prime minister and cabinet that are collectively responsible for the legislature. There are four countries with a semi-presidential constitution in this region - Armenia, Azerbaijan, Georgia, and Kyrgyzstan. The authors introduce the concept of semi-presidentialism, place the countries in a general post-Soviet context, and compare them with Kazakhstan. They investigate the relationship between semi-presidentialism in the formal constitution and the verticality of power in reality, explore the extent to which semi-presidentialism has been responsible for the relative performance of democracy in each country, and chart the relationship within the executive both between the president, prime minister and ministers, and between the executive and the legislature.