Zeolitic materials are the heterogeneous catalysts that have the highest annual production and are used in numerous acid-catalyzed reactions. Nowadays, hydrocarbon transformations, such as cracking, alkylation, and isomerization, are preferably conducted using these environmentally friendly microporous solid acids. In the general shift from homogeneous towards heterogeneous catalysis, zeolites play a key role. The rational design of these inorganic materials with highly crystalline structure is warranted both in academic and in industrial research. A proper chemical composition, a hierarchical porosity, an appropriate crystal size have, therefore, to be combined with a proper shape at the reactor level.