Modern terminology in Romanian corresponding to the norms and terminological rigors begins at the end of the 18th century and the beginning of the 19th century, from the appearance of the first grammars and lexicographical works. The analysis of the lexicon of Dimitrie Cantemir's work demonstrates that the terms used by the author had a significant contribution to the establishment of specialized languages. Dimitrie Cantemir's work is the expression of the transition from an old (medieval) phase to the functioning of specialized languages according to the criteria established later, due to the scholar's erudition, which tends to develop the Romanian language, especially by enriching the lexicon unable to reproduce all social ideas and realities. Dimitrie Cantemir gives the neological lexicon a very wide framework, the variety of neologisms, their impressive number, their scholarly nature and their use in order to give the Romanian language a high character, determined by necessity. Most of the medical terms of that period have a popular origin, coming from Greek and Latin, the popular ones almost disappeared, only some can be found in some languages, some terms were taken from glory and adapted to the Romanian phonetic system. In Dimitrie Cantemir we find for the first time a richer medical terminology. This fact is important, because writings with medical content in Romanian appear later, in the middle of the 18th century.