In this paper, the exhaust emissions of a diesel engine operating with different nanoparticles additives in diesel-biodiesel blended fuels were investigated. Firstly multi wall carbon nano tubes (CNT) with concentrations of 40, 80 and 120 ppm and nano silver particles of 40, 80 and 120 ppm with nano-structure were produced and then added as additives to the diesel-biodiesel blended fuels. A four-stroke six cylinders diesel engine was fuelled with the new fuels and operated at different engine speeds. The experimental results showed that CO₂ emission increased by 17% with an increase in nanoparticles concentrations at diesel-biodiesel blended fuel. Also, CO emission with nanoparticles added to biodiesel-diesel fuel was 25.17% lower than neat diesel fuel. The results showed a decrease up to 28.56% in UHC emission using the silver nano-diesel-biodiesel blended fuel. NOx emission increased with adding nanoparticles to the blended fuels compared to the neat diesel fuel. The experimental results demonstrated that silver & CNT nanoparticles can effectively be used as additive in diesel-biodiesel blended fuel in order to enhance complete combustion of the air-fuel mixture and reduce the exhaust emissions. Consequently the nano biodiesel can be considered as an alternative and environment friendly fuel for CI engine.