The paper presents findings on the study on land cover changes and their determinants in the coral rag ecosystem of the South District of Unguja. The study is based on data extracted from the 1975, 2009, and 2014 satellite images using remote sensing and geographical information systems (GIS) techniques. Additional data were collected through structured interviews in a household survey, focus group discussions, key informant interviews, transect walks and observation. The major changes detected in the study area from 1975 to 2014 were the decline of forests by 28.3% from 43.31 to 15% and the increase of semi-open forest and bush by 24.16% from 10.54 to 34.7. During the same time, settlements increased from 0.1to 4.9%. Different factors both direct and underlying have caused land cover change in the study area. Direct causes include shifting cultivation, cutting of wood for commercial firewood, charcoal, pegs and cutting of sticks for seaweed farming. The underlying ones are population growth, policy reforms and policy failure, land tenure insecurity, soil as well as the terrain and underlying rocks. If not properly addressed, land cover changes are likely to affect either positively or negatively the wildlife as well as the livelihoods of the communities. Investment in intensive cultivation and alternative sources of energy is required to reduce over-utilization of forest resources and to improve conservation and people's livelihoods.