Hierarchical ZSM-5 was synthesized without organic template and seed-assisted from the abundant natural source, kaolin, via the facile 1-step hydrothermal process. The hierarchical structure was able to be well-controlled solely on the Na2O/Al2O3 ratio of the precursor. This method is not only simple but greener from the scientific point of view. As revealed, kaolin layered structure that dispersed in the highly alkaline NaOH medium prompts the formation of zeolite as the molecular organization is induced. The excess of NaOH acts as desilication agent after the formation of zeolite as proven by the 29Si MAS NMR data. Display omitted •Synthesis of hierarchical ZSM-5 from kaolin source without organic template.•The facile 1-step hydrothermal process of the formation of hierarchical ZSM-5.•The hierarchical structure was able to be well-controlled by NaOH.