Heterogeneous catalytic ozonation using natural zeolite has been recently reported. However, there is a lack in the information related to the influence of zeolite active surface sites in this combined system. This work presents experimental results on the effect of zeolite chemical surface properties on catalytic ozonation. Zeolite samples with different chemical surface compositions were prepared from natural zeolite. The effect of pH, and the presence of radical scavengers were assessed at laboratory scale. Results obtained here indicate that hydrous oxide sites present on zeolite surface (S-OH2 +, S-OH, S-O-) play a key role on the catalytic ozonation mechanism.