Open Journal of Forestry, 11, 83-107.Agroforestry and beekeeping are widely promoted as prospective Nature- Based Income Generating Activities (NIGAs) to improve livelihoods while at the same time enhancing biodiversity conservation in degrading agro-ecologies. These activities can diversify and increase famers’ incomes and support in- stinctive biota and fauna resilience. However, evidence to showcase and com- pare their long-term benefits is scant. We use the case of Uluguru Mountains in Tanzania to evaluate and compare viability of agroforestry and beekeeping projects using the Cost Benefit Analysis (CBA) approach. The results of anal- ysis yielded positive NPVs for both agroforestry and beekeeping projects at discount rates not higher than 8.2% and 8.5% respectively. Overall, the com- parison of economic viability between agroforestry and beekeeping projects revealed that the former was relatively more profitable than the later in terms of both the NPV and Benefit Cost Ratio (BCR) criteria. However, the Internal Rate of Return (IRR) for beekeeping was slightly higher than that of agrofore- stry. Yet, we underscore the fact that these two projects can jointly be imple- mented to enhance livelihoods of farmers and support biodiversity conserva- tion in the study area and other parts with similar agro-ecologies in develop- ing countries. However, farmers in these agro-ecologies need to be supported by governments and non-government development partners in terms of training and inspiration to shift from orthodox farming to sustainable NI- GAs.