This paper described a successful communal system of natural forest management supported by the Plan Piloto Forestal project in Quintana Roo, Mexico. Ten neighbouring 'ejidos', communities based on common ownership of a large area of farm land, took over management of local forests from a logging company in 1983. With initial technical assistance from extension agents and GTZ, the ejidos established a new institution, the SPFE, to run the forests. Local technicians were trained and a careful foresterial plan aimed at ecological sustainability was developed. The SPFE quickly adopted an active strategy of negotiating better prices and the inclusion of secondary timber, establishing a competitive rate of return. The success of the arrangement was largely due to the many favourable underlying conditions, which might limit broad applicability, but nonetheless vindicated participatory forest management.