The article attempts to describe and generalize the features of the use of phraseological unit priemnyi pokoi. Historical and modern examples of the use of this term in medical literature, in fi ction and in offi cial language are given, the process of phraseologization of the combination is described. The article traces the displacement of the phraseological unit priemnyi pokoi to the periphery of the language under the infl uence of the nomenclature stereotypical combination of the words priemnoe otdelenie, explains the reasons for the preservation of the combination priemnyi pokoi in informal speech. Early examples of the use of the combination of words priemnoe otdelenie are given. The article compares the stylistic and semantic characteristics of the terminological phraseological unit priemnyi pokoi and the nomenclature stereotypical combination of words priemnoe otdelenie. The article draws conclusions about the signifi cant advantages of the term priemnyi pokoi as an integral part of the vocabulary of medicine.