Evidence suggests that differences in regulatory requirements of individual economies may actually impede gains from trade liberalization, while a smooth functioning, transparent regulatory system can have positive effects on trade and investment flows. This has increasingly induced policy makers to pay closer attention to the complementarities and interconnectedness between domestic regulatory reform and market openness. This study focuses on identifying regulatory processes, tools and policies adopted in order to support market openness and improve trade and investment opportunities. Although the elaboration of a market openness assessment toolkit is still at early stages, a number of promising approaches do come out, even if a number of issues call for further attention and work, on which the trade policy community might wish to focus in the future.