Biodiesel considerably decrease the CO and CO₂ emissions and its blends reduce NOₓ emissions. In this work, binary blends of biodiesel from Cotton, Jatropha and Neem with diesel were prepared in form of B5C, B10C, B15C, B20C, B25C and B30C for Cotton at 5%, 10%, 15%, 20%, 25% and 30% respectively. This was similarly done for Jatropha and Neem biodiesel designated as B5J and B10N, etc. A set of multi-blends of all the 3biodiesel with diesel were also prepared. The fuel samples were used to run a Cusson’s 4-cylinder, stationary diesel engine with data logger system. The exhaust emissions of fuel during the combustion process were measured using IMR 1400 gas analyser to detect the composition of flue gases at 1500 rpm, 2000 rpm, and 2500 rpm engine speeds. It was found that, B20C has the lowest exhaust temperature, lowest percentage losses, highest combustion efficiency, and lowest NOₓ and CO₂ emissions, but highest SO₂ emissions although with negligible percentage. The binary biodiesel blends are better than the multi-blends in terms of exhaust emissions reduction.