Zacharovana Dolyna is a Ukrainian national geological reserve that was established in 1978. In 2009, it formed the basis for establishing the National Nature Park Zacharovany Krai, and now it is the most interesting part of the park regarding its environmental diversity. Investigations of the biodiversity of this park remain at the initial stage, and data on bryophytes are not available so far. We identified 114 bryophyte species, including 45 species that were proven new to the Volcanic Carpathians. We performed a taxonomic analysis of the bryoflora and clarified that Mniaceae (10 species), Polytrichaceae (8 species), and Brachytheciaceae (8 species) were the species richest families; the last one mentioned belongs to the three species richest families of the Ukrainian Carpathians. Most species of the families Mniaceae, Polytrichaceae and Brachyteciaceae prefer overmoistened ecotopes prevailing in the studied area, including wet rocks and stones along streams. A special feature of the Reserve is that a significant percentage of the species were found on stony substrates. The bryophyte flora documented here also includes the species of conservation concern. Pseudohygrohypnum fertile is considered vulnerable, endangered, or rare in many European countries, while Dicranum viride is the Bern Convention species. Neckera pennata is especially rare for Zakarpattia and is a vulnerable species listed in the Ukrainian Red List of Bryophytes. We registered a high species diversity of bryophytes in a relatively small area of the Zacharovana Dolyna Reserve due to the high diversity of potential bryophyte substrates and microhabitats.