This chapter explores the interplay between sex and socialism in the Soviet Union, Cold War Eastern Europe, China, Cuba, and Vietnam. It examines how sex was legislated, represented, and managed by the state, placing this analysis within the context of religious beliefs and cultural mores, Westernization and globalization, and generational change. Considering sexuality as both a procreative and a recreative practice, it demonstrates that concerns about regime consolidation, demographic growth, public health, and popular legitimacy, more so than commitment to gender and sexual equality or personal pleasure, shaped state approaches to sex. Yet while the state instrumentalized sex for the purpose of building socialism, some experts were genuinely devoted to enhancing citizens’ knowledge of sexual health and satisfaction, eschewing ideological concerns. Meanwhile, socialist regimes had to contend with traditional values and religious influences, which were often contrary to the modernizing impulses and progressive policies states hoped to institute, and, as socialism wore on, younger generations who supported liberalizing tendencies. They also had to contend with external forces, such as the opening to Western culture. Thus, state policies and representations of sexuality varied across time and space, affecting individuals in different ways.