He headed the project "Russia and Central Europe in the Middle Ages" in the World History Institute of the Russian Academy of Sciences.
Considered a disciple of Vladimir Pashuto, Nazarenko advocated tighter integration of historiography with the auxiliary disciplines of genealogy, numismatics, and sigillography.
This approach allowed him to identify and publish a number of new (mostly foreign) sources on the history of Kievan Rus.
Nazarenko's major findings were summarized in a monograph International Relations of Ancient Rus.
Upon its publication in 2009, the book won Nazarenko the Macarius Award of the Russian Orthodox Church.