With the state withdrawing from controlling the food markets in Vietnam, the decision-makers and researchers in social sciences are faced with the question of the performance of private markets, and of the role of the public authorities in regulating them. Economic literature has given traditional treatment to the question of market performance through the paradigm of pure and perfect competition which provides the basis for structure-conduct-performance analyses. Institutional economics has recently provided tools for understanding the internal market organization mechanisms. The results of quantitative and qualitative surveys on the vegetable chains supplying Hanoi challenge the common descriptions of the disorganization of private markets. The organization of commodity chains is in line with some of the predictions of transaction cost economics as contractual arrangements are more frequently observed in the channels where the demand for information on quality and timeliness of supply is higher. In addition to transaction costs, the small scale of production and transport is a major cause for the identified organizational patterns including the integration of peri-urban production and assembling stages. The paper concludes by suggesting some areas for public involvement e.g. credit for production and transport means, technical and market information dissemination aimed at the development of off-season supply, promotion of producers' assembling associations.