This paper presents phytosociological analyses of oak-ash-elm forests of Nyírség, NE Hungary. These climatically azonal forests grow in habitats where the soil is under the continual influence of the groundwater table, which maintains rather mesic conditions. They are particularly rich in Fagetalia elements (Actaea spicata, Allium ursinum, Anemone ranunculoides, Asarum europaeum, Athyrium filix-femina, Cardamine bulbifera, Carex pilosa, Cerastium sylvaticum, Chaerophyllum aromaticum, Corydalis cava, Dryopteris filix-mas, Epipactis helleborine agg., Euphorbia amygdaloides, Galeobdolon luteum, Galium odoratum, Hedera helix, Isopyrum thalictroides, Lathraea squamaria, Lathyrus vernus, Lilium martagon, Majanthemum bifolium, Mercurialis perennis, Milium effusum, Polygonatum multiflorum, Pulmonaria officinalis, Ranunculus cassubicus, Salvia glutinosa, Sanicula europaea, Scilla vindobonensis, Stachys sylvatica, Stellaria holostea etc.) typical in the submontane regions of this part of Europe. It is possible that they are remnants of the vegetation dominating the region under the less continental and more moist climate during the Beech phase (2500–800 BC) of the Holocene.