We have used a combination of traditional morphological examination and molecular DNA analysis to characterise 16 moss specimens collected from the Mawson Escarpment and Clemence Massif, exposures of bedrock and glacial debris in the southern Prince Charles Mountains of East Antarctica. The nuclear ribosomal ITS region and the chloroplast rps4 gene were sequenced and compared with those of other mosses known from coastal East Antarctica. The moss specimens from the southern Prince Charles Mountains were identified as Ptychostomum pseudotriquetrum (Hedw.) D. T. Holyoak and N. Pedersen, Schistidium antarctici (Cardot) 'L.I. Savicz & Smirnova' and Coscinodon lawianus (J.H. Willis) Ochyra. These constitute a new record for S. antarctici in the Prince Charles Mountains, and confirm and extend southwards previous records for P. pseudotriquetrum and C. lawianus in the region.