In the latest years, much attention have been raised on the contribution of textile washing processes to the global release of microplastics to marine environments. However, microplastics of fibrous shape have been found ubiquitous beyond just seas and oceans, but also in freshwater systems, soil and atmospheric deposition. This environmental problem is not only related to synthetic textiles like polyester, polyamides and acrylic, since also natural or artificial fibres like cotton and rayon have been detected in environmental samples. Therefore, the widespread occurrence of microfibres (synthetic, artificial or natural fibres ¡ 5 mm) in different environmental compartments, calls for more researches on the sources of this pollution and on parameters of influence. In this scenario, the present work aims to investigate the release of microfibres from garments to water by laundering and to air by wearing. In order to understand the influence of textile parameters on the release, polyester garments with different material compositions, fabric structure, yarn twist, fiber type, and hairiness, were characterized and analysed. Tests to assess the release to water were performed by using a commercial washing machine and a multistep filtration procedure of the related wastewater. Tests to evaluate the release to air were carried out by involving volunteers wearing the selected garments in a controlled clean room and using passive samplers. Results showed how the release to both media is influenced by textile parameters and that the release of microfibres to air could be as important as that to water. Mitigation actions at the textile design stage should be considered and assessed to reduce the release of microfibres to both water and air.