On the basis of self-determination theory (R. M. Ryan & E. L. Deci, 2000) and cultural descriptions drawn from H. C. Triandis (1995), the authors hypothesized that (a) individuals from different cultures internalize different cultural practices; (b) despite these differences, the relative autonomy of individuals' motivation for those practices predicts well-being in all 4 cultures examined; and (c) horizontal practices are more readily internalized than vertical practices across all samples. Five hundred fifty-nine persons from South Korea, Russia, Turkey and the United States participated. Results supported the hypothesized relations between autonomy and well-being across cultures and gender. Results also suggested greater internalization of horizontal relative to vertical practices. Discussion focuses on the distinction between autonomy and individualism and the relative fit of cultural forms with basic psychological needs.