In the American Society for Apheresis (ASFA) guidelines, the abbreviation for therapeutic plasma exchange is standardized as TPE. However, the term PLEX (derived from PLasma EXchange), among others, is not infrequently encountered in clinical practice and in publications. Search queries were performed in PubMed using therapeutic plasma exchange, plasma exchange, “therapeutic plasma exchange,” “plasma exchange,” TPE plasma, PLEX plasma, PEX plasma, TPE, PLEX, and PEX. As compared to TPE, the term PLEX was more commonly used in articles related to neurology, nephrology, and rheumatology, while the term PEX was used in some hematology, apheresis, and medicine journals to a lesser extent. Unsurprisingly, the terms PLEX and PEX were rarely used in articles published in apheresis and transfusion medicine journals. The use of these differing terms may lead to confusion among patients and healthcare providers across medical specialties. Apheresis providers should advocate for the use of standard terminology.