ABSTRACT Introduction. Bryological knowledge of the mountains of mainland Greece remained very fragmentary until the later part of the twentieth century, but increased exploration in recent years has begun to document the flora and produced significant records. Methods. As part of ongoing studies on the Greek bryophyte flora, the author, accompanied by Marko Sabovljević, visited four mountains in Northern Greece (Mt Timfi, Mt Varnous, Mt Voras, Mt Vermio) in 2003 to record the bryophytes. Further collections were made by the author in 2017–2019. Key results. Nine species new for Greece are reported from the author’s collections: Diplophyllum taxifolium, Mannia gracilis, Scapania subalpina, Solenostoma confertissimum, Bryum creberrimum, Rhizomnium pseudopunctatum, Roaldia dolomitica, Serpoleskea confervoides and Sphagnum flexuosum. Three further species, Metzgeria pubescens, Scapania cuspiduligera and Grimmia unicolor, are formally documented for the country. Previous reports of Scapania subalpina and Serpoleskea confervoides in Greece are erroneous. The presence of Diplophyllum obtusifolium on Mt Voras is doubtful, but it has been found recently in the Greek Rhodope Mountains. An extreme form of Pohlia elongata var. greenii, a variety which is new for Greece, is discussed and illustrated.