Biodiesels from Indian origin based oils such as Jatropha and Karanja have been experimented in number of ways by different researchers across the world. The literature concludes that these biodiesels under-perform in a compression ignition engine and this can be attributed to their poor physio-chemical properties. Several researchers have tried blending them with diesel and tried to address the issue of under-performance. But, the fact that diesel gets extinct in near future suggests that it is better not to rely on diesel, again. Alongside, waste disposal and non-biodegradability of waste plastic has become a serious threat to humankind. Therefore, an attempt to blend biodiesels with pyrolysis oil derived from waste plastic is made in the present study. The biodiesels considered for the study include jatropha and karanja. It was observed that blending plastic oil to Jatropha and Karanja biodiesels reduced their viscosities to a greater extent and this can help in improved spray characteristics. Plastic oil also improved the calorific value and density of biodiesels significantly, which can reduce the specific fuel consumption and reduce it down to that of diesel. The flash point of the biodiesels decreased by blending them with plastic oil and this seemed to be a disadvantage of dilution of biodiesels with it. However, the study suggests that the option of blending plastic oil over diesel, not only addresses the issue of under-performance of biodiesels but also the issue of non-biodegradability of waste plastic