After the publication of his study of the "French moralists" in 1893 and a critical work on Vladika Petar II Petrović-Njegoš of Montenegro's famous poem The Mountain Wreath (Gorski Vjenac), in 1894, he was appointed as assistant professor in Serbian Literature at the university, his alma mater, in 1895.

Pavle complimented Jovan Skerlić's work by publishing an overview of Serbian literature (1913) that emphasized early literary history and the oral tradition that followed.

His method of literary history combined archival research, philosophical polemics, and comparative perspective, discourse, inspired by other contemporary European literatures, gave a touch of elegant and witty lightness to anecdotal narratives, and soon influenced a younger generation of critics and essayists.

His literary history and his numerous specialized studies on nineteenth-century Serbian theater and other matters were considered a standard for more than 60 years, along with Skerlić's work, which was, to be sure, ideologically more attractive.

Pavle Popović corresponded with the following scholars Milivoy S. Stanoyevich, George Rapall Noyes, John Dyneley Prince, Robert William Seton-Watson, Watson Kirkconnell, and many other academics.