Diethyl Ether (DEE) is a promising oxygenated renewable bio-base resource fuel used for diesel engines, owing to its high ignition quality. An experimental investigation has been carried out to evaluate the effects of DEE blends with diesel on the combustion, performance and emission characteristics of a direct injection diesel engine. The engine tests are carried out for 10%, 25%, 50%, 75% and 100% of the full load. In this study, 2%, 5%, 8%, 10%, 15%, 20% and 25% of DEE (by volume) are blended with diesel. Beyond 25% DEE blend, the viscosity and density of the blended fuel reduces as compared to the acceptable limits, that can further reduces the lubricity and create potential wear problems in sensitive fuel injection pump and fuel injector design.The laboratory fuel tests showed that DEE can be mixed in any proportion in diesel fuel. The blended fuel retains the desirable physical properties of diesel fuel but includes the cleaner burning capability of DEE.The experimental results indicated that the blends of DEE with diesel up to 25% are possible. The most favourable blend found is DE15D resulting in low smoke, low NOx, high brake thermal efficiency and low brake specific fuel consumption as compared to other blends and neat diesel. In addition, it is observed that unburned hydrocarbon increases and CO emissions reduces as compared to the neat diesel.