Research on alternative fuels is increasing due to environmental concerns and diminishing fossil fuel reserves. Biodiesel is one of the best renewable replacements for petroleum-based fuels. This paper examines the potential of biodiesel obtained from Jatropha curcas and Moringa oleifera oils. The physico-chemical properties of J. curcas and M. oleifera methyl esters were presented, and their 10% by volume blends (JB10 and MB10) were compared with diesel fuel (B0). The performance of these fuels and their emissions were assessed in a fully loaded multi-cylinder diesel engine at various engine speeds. The properties of J. curcas and M. oleifera biodiesels and their blends agreed with ASTM D6751 and EN 14214 standards. Engine performance test results indicated that the JB10 and the MB10 fuels produced slightly lower brake powers and higher brake specific fuel consumption values compared to diesel fuel over the entire range of speeds. Engine emission results indicated that the JB10 and MB10 fuels reduced the average emissions of carbon monoxide by 14 and 11%, respectively; and hydrocarbons by 16 and 12%, respectively. However, the JB10 and MB10 fuels slightly increased nitrous oxides emissions by 7 and 9%, respectively, and carbon dioxide by 7 and 5%, respectively compared to B0. In conclusion, J. curcas and M. oleifera are potential feedstock for biodiesel production, and the JB10 and MB10 blends can replace diesel fuel without modifying engines to produce cleaner exhaust emissions.