A bioeconomic model of reservoir aquaculture in northern Vietnam, called BRAVO, is presented. The biological model is based on a conventional von Bertalanffy growth function and the economic model is a net revenue function. The greatest source of costs for the operation are restocking costs (75 percent) and contract labour costs (18 percent). The net revenue of the operations is approximately 9.7 million VND (approximately US$615). The greatest area of uncertainty in the model is harvesting efficiency, which is very low (ranging between 5 and 26 percent). The harvesting efficiency, along with the length of time between stocking and harvest, has a large impact on net revenue. Reservoir aquaculture has developed in an ad hoc way in Vietnam. Including reservoir aquaculture into government fisheries development plans with research focused on development of fingerling production, preparation of flooded land for aquaculture production and strengthening institutional arrangements for reservoir leasing and credit arrangements, is likely to lead to capitalisation, increased investment and therefore greater revenues for local fishing populations.