The possible depletion of fossil fuels has created the need for alternate fuels worldwide and engine developers are prompted to investigate the viability of such fuels. Further, stringent emission norms have created the need for low emission engines. The objective of this work is to evaluate the effect of diethyl ether in biodiesel-diesel blends on the performance and emission characteristics in a Premixed Charge Compression Ignition-Direct Injection (PCCI-DI) engine. Biodiesel obtained from cotton seed oil is used for this study. PCCI-DI engine is operated with main injection and pilot injections with varying percentages of DEE along with 20% biodiesel blended with neat diesel. The emission characteristics show a discernible reduction in emissions (NOx, CO and HC) vis-a-vis biodiesel-diesel blends. Benefits like reduction in the quantum of smoke produced and improvement in Brake thermal efficiency are also noticed in specific cases. (C) 2017 Elsevier Ltd. All rights reserved.