This article presents a comprehensive kinetic model for thermal cracking of waste cooking oil using monomolecular lumped kinetics. The chemical lumps were classified on the basis of carbon number range of the hydrocarbons and a first order irreversible monomolecular cracking kinetics was considered for finding the product concentration in a reactor. Arrhenius kinetic law was applied for determining temperature dependency of the apparent kinetic constants included in the model. The parameter reduction was performed by calculating the preexponential factors through transition state theory and statistical thermodynamics concepts. The activation energy of the reactions was estimated through hybrid optimization using experimental data available in the literature. The proposed kinetic model for thermal cracking of waste cooking oil exhibits good agreement with the experimental data. Furthermore, the present kinetic analysis reveals that all parallel reactions from waste cooking oil are dominant for producing hydrocarbons in a product lump as compared to reactions in series and further cracking of product lumps. (C) 2015 Elsevier Ltd. All rights reserved.