Abstract: Internal combustion (IC) engine knock is characterized by uncontrolled autoignition of a mixture of fuel and oxidizer, whereas homogeneous charge compression ignition (HCCI) relies on controlling the autoignition to achieve a favorable engine performance. This study investigates the autoignition of Primary Reference Fuels (PRFs) using the kinetic model by Curran et al. (2002). The CHEMKIN (2006) software is used to facilitate solutions in a constant volume reactor and a variable volume reactor representing an internal combustion engine. Both models assume homogeneous mixing of fuel and oxidizer. Experimental data for shock tube ignition delay times and HCCI engine pressures and temperatures have been obtained from literature. First, shock tube data is compared with the present predictions in the constant volume adiabatic reactor for a range of inlet temperatures and fuel octane numbers. CHEMKIN's IC engine model with a heat transfer correlation is then used to reproduce the engine experimental data. Finally, a parametric study of the effect of inlet pressure, inlet temperature, octane number, fuel/air equivalence ratio, and exhaust gas recirculation (EGR) on the autoignition of PRF/air mixtures is conducted.