Thermal radiation, although considered an important mode of heat transfer in high temperature conditions, is often neglected in fire modeling, mainly due to the complex physics involved. The aim of this study is to provide modelers with guidance on the engineering treatment of radiation transfer; two widely used radiation models are reviewed and their performance is assessed in a benchmark experimental enclosure fire case. The discrete transfer and the six-flux radiation models are compared in terms of computational efficiency, ease of application, and predictive accuracy. The predictions are evaluated as part of a complete prediction procedure involving the modeling of the simultaneously occurring flow, convection, and radiation phenomena. The results have demonstrated that the effect of thermal radiation is important, even in small fires. Comparison between the two models indicates that the simple six-flux model suffices for small compartment fires, up to 100 kW.