Abstract: Mesoporous zeolites play a crucial role in several potential applications including heterogeneous catalysis due to fast mass transfer along with size and shape selectivity. A new approach was developed for synthesizing single-crystalline zeolites with interconnected mesopores using a nonsurfactant cationic polymer as a dual-function template. The designed strategy for secondary porosity generation showed a remarkable enhancement in catalytic reactions that suffer from diffusional limitations. Their superior catalytic performance can be attributed to the combination of high-density mesopores and zeolitic frameworks. Moreover, coupling the accessibility and shape selectivity associated with the designed hierarchical zeolites with the reactivity of metal atoms makes these molecular sieves of particular attraction as catalysts.