Martinet passed his agrégation in English and received his doctorate after submitting, as is traditional in France, two theses: La gémination consonantique d'origine expressive dans les langues germaniques and La phonologie du mot en danois. From 1938 to 1946 he served as a director of studies of the École pratique des hautes études (EPHE). After World War II he moved to New York City, where he would remain until 1955.
In New York, he directed the International Auxiliary Language Association up to the end of 1948 and taught at Columbia University, where he served as chair of the department from 1947 to 1955. Also, he became editor of Word, a linguistics journal. In 1955 he returned to his position at EPHE and took up a chair in general linguistics at the Sorbonne, and then at Paris V. He continued to be active professionally by serving as president of the European Linguistic Society and founding both the Society for Functional Linguistics and the journal La Linguistique.
The Prague School of linguistics was one of Martinet's main influences, and he is known for pioneering a functionalist approach to syntax, which led to a violent polemic with Noam Chomsky. He wrote over twenty books - on topics ranging from historical linguistics (Économie des changements phonétiques, 1955) to general linguistic theory. His most widely known work, Elements of General Linguistics (1960) has been translated into 17 languages and has influenced a generation of students, both in France and abroad.
Other works include General Syntax (1985), The Function and Dynamics of Language (1989), and an intellectual autobiography entitled Memories of a Linguist and the Life of Language.
Martinet was married twice: