The fungal cell wall is a complex structure composed of chitin, glucans and other polymers, and there is evidence of extensive cross-linking between these components. The wall structure is highly dynamic, changing constantly during cell division, growth and morphogenesis. Hydrolytic enzymes, closely associated with the cell wall, have been implicated in the maintenance of wall plasticity and may have roles during branching and cross-linking of polymers. Most fungal cell wall hydrolases identified to date have chitinase or glucanase activity and this short article reviews the apparent functions of these enzymes in unicellular and filamentous fungi, and the mechanisms that regulate enzyme activity in yeasts.