In this investigation, attention is focused to find out the effect of combustion chamber shape on the performance and emission characteristics of a stationary diesel engine fuelled with methyl esters of vegetable oil. Toroidal shape combustion chamber was fitted in a 4.4kW naturally aspirated single cylinder Direct Injection Compression Ignition (DI CI) engine and tests were conducted when fuelled with diesel and Corn oil Methyl Ester (COME). COME had shorter ignition delay than diesel because of its better spray characteristics. From performance characteristics it was observed that COME had slightly lesser thermal efficiency compared to diesel. The specific fuel consumption of the COME is slightly higher than that of diesel. HC, CO and Smoke density and soot concentration emissions are lesser for COME than diesel. At part load condition NOx emission was found to be higher for COME than diesel.