The rising demand for fuel presents a major challenge to globalization. However, transportation business has advanced remarkably in mitigating this issue by commercializing alternative fuels like ethanol, biodiesel, liquefied petroleum gas, and compressed natural gas. In the current investigation the prospective utilization of blends of pyrolysis bio-oil and diesel is ascertained as a substitute fuel for powering diesel engine. Blends, which consist of 10% to 30% pyrolysis bio-oil, are referred to as BO10, BO20, and BO30. The bio-oil was produced from pyrolysis of deccan hemp seed-cake. The study analyzed various performances, emission and combustion parameters, including brake thermal efficiency, exhaust gas temperature, carbon monoxide, and hydrocarbon, oxides of nitrogen emissions, heat release rate and rate of pressure rise. Results showed that the variance of brake thermal efficiency between diesel and BO20 blend was only 2.61%. Exhaust gas temperature for the BO20 blend was also lower compared to diesel. Carbon monoxide, hydrocarbon, oxides of nitrogen and smoke emissions were in proportion to diesel emissions. Based on engine test results, the BO20 blend has the potentiality to serve as substitute fuel, with a 20% blending ratio into diesel. This research provides understanding the feasibility of using pyrolysis bio-oil as a sustainable alternative to diesel fuel