Due to the rapidly increasing energy demand, the world needs to focus more on identifying alternative energy sources like biofuels and energy conservation techniques that enhance the efficiency of various systems. A cogeneration (CHP) system is one of the most emerging techniques for achieving the goal of energy conservation by providing useful power (electricity) and heating simultaneously. So the current study proposes a diesel engine-driven CHP system that is fueled with different blends of biodiesel. The objective of the current study is to investigate the impact of Eureka Sativa oil biodiesel on waste heat recovery, performance, and emission characteristics of diesel engine driven combined heating and power generation system. The cogeneration unit is developed by connecting the exhaust pipe of a single-cylinder, four-stroke diesel engine with a heat exchanger. The pure diesel, along with 10%, 15%, 20%, and 25% by volume of biodiesel, was used as fuel for the cogeneration unit. The AVL Di-Gas 444N multi-gas analyzer was utilized to evaluate the engine exhaust gas emissions. Diesel fuel has the highest brake thermal efficiency and the lowest brake specific fuel consumption (BSFC). B20 has the highest brake thermal efficiency and the lowest BSFC among all blends of biodiesel. Also, B20 has better emission characteristics than all other blends of biodiesel. The exhaust gas temperature and waste heat recovery increase with the percentage of biodiesel in the blends. The B25 has the highest overall efficiency (38.49%) among all blends, which is 1.93 % lower than pure diesel. However, result analysis revealed that B20 is the best fuel among all biodiesel blends in terms of engine performance and emission formation. Whereas B25 is a better fuel in terms of WHR and overall cogeneration unit efficiency.