Full text can be accessed at http://www.sciencedirect.com/science/article/pii/S0308597X16302160Alternative livelihood programmes are often used in multipleuse marine protected areas as incentives, compensation for lost opportunities, or as intervention strategies for poverty alleviation. Yet little is known about their impacts on biodiversity conservation and the well-being of the targeted communities. This study focuses primarily on alternative livelihood projects undertaken among selected groups of individuals, in six villages, located in the Mnazi Bay-Ruvuma Estuary Marine Park (MBREMP), Mtwara district, southern Tanzania. The aim was to investigate how the processes involved in the implementation of these new livelihood activities contributed to the expected outcomes of providing good returns to reduce community's dependency on the sea and improve conservation. Data were collected through focus group discussions with selected members of local community, who actively took part in the projects; key informant interviews with conservation personnel and district fisheries officials; questionnaire surveys of a random sample of project beneficiary households; and a review of pertinent documents. The overwhelming majority of survey respondents (90%) reported that the projects were allocated inappropriately. Interviews and focus groups further revealed that the purpose of alternative projects was not sufficiently clear and that many beneficiaries perceived that these projects were initiated simply to comply with the MBREMP regulations. Overall, 70% of survey respondents stated that the project activities could not compete with the income gained from fisheries. An analysis of documents further revealed that almost all projects began to flounder when funding from the MBREMP came to an end. This was because they were not supported beyond the pilot phase and, thereafter, insufficient revenue was generated to maintain running costs. Improved targeting and design of livelihood interventions will ensure that the projects achieve the goals of providing alternatives for fishers, increasing well-being and improving biodiversity conservation.