This work is focusing on the synthesis and application of new potential ionic liquids (ILs) for biodiesel production from waste palm cooking oil. For this propose total eleven ionic liquids were synthesized containing various types of cations and anions and characterized with nuclear magnetic resonance (NMR), fourier-transform infrared (FTIR) and elemental analyser (CHNS). The Hammett acidity of the ionic liquids were determined using Ultraviolet (UV) visible spectrometer and correlated with their catalytic properties. The process of biodiesel preparation has been optimized with respect of different factors (catalysts concentrations, methanol to oil ratio, temperature, agitation speed and time) affecting the transesterification reaction. The highest yield of 96.25 for 3-methyl-1-(4-sulfo-butyl)-3H-imidazol-1-ium trifluoromethanesulfonate BSMIMCF3SO3 was obtained under optimal conditions. The obtained product was characterized using gas chromatography (GC), NMR, FTIR, Thermogravimetric analysis (TGA) techniques. The physicochemical properties like kinematic viscosity, flash point, density etc were determined and compared with the standard of American Society of Testing Materials (ASTM) and European Standard (EN) methods. The by-product of reaction i.e. glycerol was further esterified to minimize the waste of glycerol. The kinetic study shows that the transesterification reaction catalysed by prepared ILs follow the pseudo-first order reaction. The kinetic energy (Ea) of the reaction was calculated around 19.89 kJ/mol. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim