This report is an output of the Better Regulation for Growth Program between the Dutch Ministry of Foreign Affairs, the UK Department for International Development (DFID) and IC, the Investment Climate Advisory Services of the World Bank Group. The reports identifies a set of minimum requirements for a well-functioning Ria light system that is tailored to the requirements of developing countries. Embracing the overall objectives and relevance of RIA, the paper explores the fundamental set of building blocks and activities required to establish and maintain a RIA light system, taking into account what it is considered as good practice. The paper argues that the following five basic criteria have to be in place for a functioning RIA system, which is referred to as "RIA light": 1) political commitment to establish and operate an effective and self sustaining RIA process; 2) a unit or group of regulatory reformers - preferably based in a central area of government - which oversees, comments and reports on the quality of regulatory proposals before decisions are made about regulation; 3) clear and consistently applied criteria and rules employed to screen regulatory proposals; 4) a transparent regulatory policy development process, which includes consultation with stakeholders; and 5) a capacity building program, involving preparation of guidelines; training of officials preparing RIA and facilitating the required cultural changes, and establishing monitoring, evaluation and reporting systems.