This article is concerned with the question of why lesbian, gay, bisexual, and trans (LGBT) rights legislation is introduced at higher levels in some cases and less so in others. To address this puzzle, the article analyzes changes in LGBT rights legislation across European Union (EU) member states between 1970 and 2009. It focuses on the diffusion of five different categories of such legislation (anti-discrimination, criminal law, partnership, parenting rights, and equal sexual offenses provisions) to new EU member states in Central and Eastern Europe, compared with diffusion patterns in older EU member states. I argue that new-adopter states are more dependent on international resources for making new issues visible and are more inclined to see policy adoption as a means to gain external legitimacy and improve reputation. The analysis reveals that the transnational embeddedness of a state's LGBT advocacy organizations is a powerful statistical explanation for successful policy diffusion to new EU member states, alongside international channels that lead to LGBT visibility among society and state authorities. In addition to lending cross-national, empirical reinforcement to some of the theoretical expectations regarding the international sources of diffusion, the results suggest variability in the determinants of LGBT policy adoption between the 15 old and 12 new EU states. Domestic factors, particularly economic modernization, are more relevant for policy adoption in the older member states, whereas the newer member states display greater dependence on transnational actors and are more influenced by international channels.