It developed right at the beginning of his career, when the scientist almost simultaneously started to work on Turkish, Tatar, Bashkir, Gagauz, Kumyk, Azeri, Turkmen, and other languages of the extensive Turkic family that soon became a subject of his specialty.
Marr began being strenuously propagandized in the Stalinist Soviet Union, Dmitriev remained alien to the attempts to discover in Turkic languages "stadial reorganizations", and to the attempts to discover in Turkic languages inflection, prefixes, etc., which did not escape even some competent foreign Turkologists.
In his last years Dmitriev's attention especially attracted the question on attitude of the Turkic languages to the category of grammatical gender.
Dmitriev wrote baseline scientific descriptions for many of Turkic languages, including Kumyk, Bashkir, Turkmen, and Gagauz.
The Gagauz language for the first time was investigated by Dmitriev, one of his two works is devoted to phonetics, and another gave its grammatical and lexical description.
Another monumental lexicographic works of Turkology was the "Russian-Chuvash dictionary" under Dmitriev editorship with a grammatical sketch the Chuvash language.
[citation needed] For 16 years (1925–1941) Dmitriev was closely connected with the Leningrad State University and Oriental Institute, where he headed the faculty of Turkic philology.
His energy and efforts led to creation of Oriental Branch at the Philological faculty of the Moscow State University, which he headed till the last days of his life.
During Dmitriev's 30-years pedagogical work he created a large number of university courses, including Turkic paleography.
His pupils work in Moscow, Leningrad, Baku, Ashkhabad, Alma-Ata, Bishkek, Tashkent, Samarkand, Kazan, Ufa, Makhachkala, Cheboksary, Yakutsk, Abakan and other cities.