The diversity of hypogeous fungi in the Pieniny Mts has been insufficiently studied. Until recently, eight species were known from this area. The aim of the present study was to gather new data on the hypogeous fungal mycobiota of this mountain range. In July and September of 2016 and 2017, sporocarps of hypogeous fungi were searched on six permanent plots established in Pieniny National Park. The dominant plant associations were beech and beech-fir forest with spruce, hazel, hornbeam and elm as accompanying trees. Over 100 samples of hypogeous fungi were gathered during the field work. They included 30 species from ascomycete genera: Elaphomyces (3 species), Genea (1), Hydnobolites (1), Hydnocystis (1), Hydnotrya (1), Leucangium (1), Pachyphlodes (1), Tuber (4), and basidiomycetes: Chamonixia (1), Gautieria (3), Hymenogaster (5), Hysterangium (5), Melanogaster (2) and Octaviania (1). Nine species were most frequent: Hysterangium nephriticum, Melanogaster broomeanus, Hydnobolites cerebriformis, Hydnocystis piligera, Hymenogaster rehsteineri, H. cf. megasporus, Hysterangium stoloniferum and Gautieria morchelliformis. Three species are first records for Poland: Hydnocystis piligera, Hymenogaster cf. arenarius and H. cf. megasporus. The hypogeous mycobiota of the Pieniny Mts now numbers 35 species.