The Biodiversity Support Program's Transboundary Project was designed to obtain an overview of, to assess opportunities and constraints for, and to draw lessons learned from Transboundary Natural Resource Management (TBNRM) developments in sub-Saharan Africa to date. Focus is on using collaborative natural resource management approaches to enhance or maintain ecosystem function and biodiversity conservation in large-scale natural systems in transborder areas. This document provides key elements of the TBNRM approach, TBNRM process and decision-making, and conclusions and future needs.