Biodiesel with small modification in its constituent has been often subjected to experimental analyses in diesel engine in order to substitute it as fuel for diesel engine. Environmental friendly aspects like biodegradability, renewability, easy and safety handling characteristics of biodiesel has been desired by all. But, the biodiesel has the negative side apart from its meritorious side. The performance and emission parameters of biodiesel like BSFC, BTE, smoke emission and NOx emission has not meet out the emission norms prescribed by statutory bodies. Nano additives are found to be helpful in improving the fuel quality of improved performance and emission characteristics. In this study copper oxide (CuO) nano particles are mixed with pongamia biodiesel and subjected performance and emission analysis of engine operating characteristics in diesel engine. The experimental results provides a constructive result of 4.01% increase in BTE, a reduction of around 1.0% in BSFC and a reduction of around 12.8% in smoke emission and 9.8% reduction in NOx emission for the blend B20CuO100.