Our country is facing the critical problem of fuel and energy deficiency. The fast depletion of petroleum reserves in the world and frequent rise in prices of crude oil led to search for alternative fuels. On the other hand, plastic waste has become a major element in garbage which does not decompose naturally and causes very serious environmental problems. In this context, pyrolysis of waste plastics is currently receiving renewed interest for getting the fuel. The properties of the oil derived from pyrolysis of waste plastics were analyzed and compared with the petroleum products and found that it has properties similar to that of diesel. In the present work, waste plastic Pyrolysis oil was used as an alternate fuel in a C.I. engine without any modification. The present investigation was to study the performance and emission characteristics of a single cylinder, four-stroke, air-cooled DI diesel engine run with waste plastic pyrolysis oil-diesel blends. Brake thermal efficiency of the engine is less than the diesel fuel operation at full load and higher at part loads. Unburned hydrocarbon and Carbon dioxides were marginally higher than that of the diesel baseline. The toxic gas carbon monoxide emission of waste plastic pyrolysis oil was higher than diesel.