Influence of biodiesel-diesel fuel blends with acetylferrocene and palladium based additives on diesel engine performance and emissions were studied experimentally. The additives were dosed into the blend fuels as 25 ppm. Bis-[N,N-dimethyl-N'-2-chlorobenzoylthioureato] palladium (II), PdL2 was prepared as palladium based additive. The engine tests were carried out in a single cylinder direct injection diesel engine at 4, 8, 12 and 16 Nm loads. The result of engine test revealed that the blend fuels with additives did not show the considerable effect on variation of cylinder pressure values. Also, specific fuel consumption (SFC) values with Ferrocene based additive showed comparatively better results than those of palladium based additives. Furthermore, CO and PM emissions decreased significantly up to 60.07% and 51.33%, respectively. Besides, at higher loads, NOx emissions values of the blend fuels increased, but decreased at lower loads. Moreover, Sound Pressure Level (SPL) and vibration acceleration values with the blend fuels decreased by 2.76% and 18.26%, respectively. As results, using of the metal based additives with dosage of 25 ppm contributed to improvement of SFC, emissions and vibration values for the diesel engines.