This report is organized as follows. Section 1 provides a survey of literature on the informal sector in Vietnam. Section 2 assesses the existing official sources and presents the new framework put in place since 2007 by the GSO with the assistance of the authors. Section 3 draws on this original experience to synthesize the global picture of the informal economy in Vietnam. Section 4 underlines the dynamics of the informal sector and informal employment, with a special focus on the impact of the global crisis (2008/09). Section 5 explores the determinants of transitions between formality and informality, while Section 6 is dedicated to gathering the previous results to elaborate policy recommendations.