Since 1975, Vietnamese communism has changed face three times. These frequent and radical institutional permutations have been unprecedented among communist countries. This paper argues that hegemonic dependence, domestic economic imperative, and elite idealism are the three main factors that determine Vietnam's institutional configuration. Among the three, dependence on a hegemon means the dominance of the developmental model and institutional preferences of that hegemon. Only when there is no hegemonic dependence do domestic economic imperative and elite idealism emerge as the crucial factors in determining institutional arrangements. Historically there have been four developmental stages for Vietnam's communist regime: independent socialism (1975–1977), orthodox socialism (1978–1985), glasnost socialism (1986–1990), and market socialism (1991–now). Among the four stages, orthodox socialism and glasnost socialism are the direct result of Hanoi's dependence on Moscow. After examining Vietnam's historical experience, we conclude that small countries' institutional choice under hegemon is extremely limited, but they regain latitude when hegemonic dependence is removed.