A study of the bryophyte of Marmore Waterfall Natural Park a very peculiar territory for its geological, biogeographical and bioclimatic traits, was carried out. The reported data were collected in the valley area of ‘Parco Fluviale del Nera’ Regional Park, where the waters are flowing and the humidity of the rocks is oozing. Research led to the identification of 101 taxa of bryophytes (21 liverworts and 80 mosses), among which two liverwort and 10 moss species are new records for the Umbria region, while four are confirmed. The study offers new outcomes on neglected aspects of the flora of central Italy and represents a considerable improvement of the floristic, biogeographical and ecological understanding of its bryophytic component. Additionally, the area turn out to be significant from the conservation point of view both nationally and internationally considering that it harbours high diversity of bryophytes species among which many rare, threatened and interesting species occur. Eighteen species of conservation interest in Italy are recorded during the latest investigation (all in category NT – near threatened). Additionally two species that are considered data deficient in Italy are present in the researched area (Conocephalum salebrosum and Fissidens curvatus). Also, there is a small populations of a species vulnerable (Marchantia paleacea), endangered (Bryum calophyllum) and data deficient (Fissidens curvatus and Barbula bolleana) in European scale.