A Law on Administrative Procedure (LAP) is an essential institutional feature of democratic and effective governments. It is a general law on executive law-making, setting out how laws and regulations should be made. The need for a LAP at EU-level is growing – to counter the EU's legitimacy deficit and to make the regulatory process more predictable and robust. At the same time, the EU regulatory “machine” faces new challenges and pressures, as it seeks to implement highly complex (risk management) regulation. Greater regulatory effectiveness depends on more transparency, evidence quality standards and participation. As such, an EU LAP appears to be the natural culmination of the EU Smart Regulation agenda. Since the European Parliament in 2013 called for the Commission to adopt a LAP-related legislative proposal, the debate has gained in visibility and political salience. This article makes the case for an EU LAP for the EU institutions, citizens and businesses – provided the Law enshrines the four key principles of good administration (transparency and consistency; public participation; public record; and accountability); it establishes clear and legally binding procedural standards; and it covers as a principle also rule-making and adjudication decisions by all EU institutions and bodies involved in the preparation, adoption, implementation and repeal of secondary legislation.