A socio-economic assessment of the Mnazi Bay – Ruvuma Estuary Marine Park (MBREMP) was carried out from March to July 2004 with the objective of increasing understanding on communities (approximately 28 000 people) who live within the Park. Understanding better these communities, the way in which they use and how much they depend on MBREMP marine resources will increase the chances of involving these communities effectively in MBREMP management, as stipulated in the Marine Parks and Reserves Act (1994), and thus increase chances of achieving sustainable resource use.