This paper reports on a study investigating the flame-quenching performance of ceramic foam. Experiments were performed primarily with methane oxygen mixtures in a vertical transparent tube ignited at the bottom-end which is open to the atmosphere. The flame quenching performance of the ceramic foam is compared to that of closely packed ceramic spheres. Based on the measured quenching mixture composition limits it is shown that for an equivalent flow path diameter the packed spheres performed better than the foam. The trend in the quenching limit results, as characterized by the Peclet number, could not be explained by one-dimensional thermal quenching theory. Experiments performed in a quenching medium with straight circular channels, similar in diameter as the effective flow diameter of the foam and closely packed spheres, indicates that the inherent flow tortuosity of the foam has little affect on the flame quenching phenomenon. Additional tests carried out in the straight channels with vastly different molecular weight hydrocarbon fuels, i.e., methane, ethylene and propane, show that preferential diffusion cannot explain differences in the measured limits compared to one-dimensional thermal theory predictions.