The paper reports the autoignition and forced-ignition temperatures (AIT, FIT) of diffusion flames obtained through an iterative method using the steady RANS simulation. An eddy dissipation concept (EDC) model is used for all simulations with either a global or a detailed reaction mechanism. The present simulations are validated by the previous measurements of Katsuki and Hasegawa (Proc. Combust. Inst. 1998, 27, pp 3135-3146) and Fotache et al. (Combust. Flame 1997, 108, pp 442-470). It is revealed that FIT and particularly AIT can be properly predicted by the present method for various combustion configurations with different reactant conditions and operational parameters.