Gas adsorption remains an attractive area of research. The hierarchical structure can reduce diffusion limitations and facilitate molecular transport, while acid sites can be used as adsorption sites. These make zeolites widely used in the field of gas adsorption. How to obtain zeolite adsorbents with better adsorption properties by modulating the hierarchical structure and acid sites is a pressing issue nowadays. This review highlights the strategies to modulate the hierarchical structure as well as the acid sites; and then explains how these strategies are achieved. The mechanism of zeolite adsorption on gases is then described in terms of these two properties. Lastly, the adsorption properties of zeolites for certain gases under specific conditions are summarised. An outlook of zeolite hierarchical structures and acid site modulation strategies is given.