The Ngorongoro Conservation Area (NCA) is a World’s Heritage site and Biosphere Reserve in Tanzania. It is the only protected area with multiple land use where both wildlife conservation and limited human activities are allowed. Despite such an important status, the area is experiencing ecosystem changes resulting from increasing human population, diversified livelihoods and tourism activities. This study was conducted to determine the trends and challenges of livelihood activities of the local Maasai and tourism in NCA and their implications on the ecology of the area. Household questionnaire interviews, key informant interviews, focus group discussions, direct field observations and secondary data reviews were applied. A total of 145 people from Enduleni, Oloirobi villages and the NCA Authority (NCAA) were involved in the study. To complement the socio-economic data, landsat MSS satellite images of 1990, 2000 and 2013 blocks were analysed to assess land use/cover changes occurring in the study area. Results indicate rapid human population growth rate of 5.6% and an increment of 1.1% of livestock population per annum. It is also noted that about 46% of cropland has increased in the studied villages. Furthermore, the Maasai who were historically pastoralists are changing to agro-pastoralists. The grasslands and other natural forests showed a decreasing trend. The decreasing trends in wildlife are being associated with the changing vegetation characteristics among other factors. Despite the ecological changes, the Maasai have remained uncomfortable with the restrictions over land use so far implemented by the NCAA. In addition, there has been an increasing number of tourists and facility development within the NCA. There were also differing views between the Maasai and NCAA, which might put the NCA ecosystem under serious threats questioning its future. Whether or not the NCA will remain a world heritage site depends on management measures taken, otherwise the disappearance of the NCA ecosystem is imminent.