The diversified and complex wetland ecosystem in Bangladesh has global significance for the concern of many environmental issues. A study of two wetlands in northeastern Bangladesh examines the different outcomes produced by community-based management (co-management) and private management. The data and outcomes of the private management systems generated in the Kawadighi Haor were compared with those of the Hail Haor, where co-management had been adopted. The results strongly indicated that, in comparison to the private management system, water bodies under co-management adopt more ecological management approaches, resulting in greater sustainability of resources and a more equitable distribution of benefits. The National Wetland Policy (2009) in practice promotes a traditional short-term leasing model that is highly susceptible to elite capture. The study also found that the biophysical condition and ecology of the Balla beel of Hail Haor were in decline before co-management began, then rapidly recovered during the co-management period, and quickly declined again when private management took control over the waterbody. The study further provides a set of recommendations for the sustainable management of wetland resources in Bangladesh and in a broader global context.