Encouraged by his father, he became an art expert at a young age and cut short his formal education in 1901 to become an employee at the auction house of Frederik Muller in Amsterdam.

While he was still occupied with this project, he donated his huge collection of sale catalogues and other documentary materials to the Netherlands Institute for Art History (RKD) at The Hague along with his personal library, in the nature of a "permanent loan."

In 1921, he completed his first work essential to art historians, Les marques de collections de dessins et d’estampes,[1] the definitive repertory identifying the collector's marks and stamps on drawings and prints, with a short descriptive biography of each owner and a description of the particular collection; the work is the essential reference for establishing the provenance of Old Master drawings and prints.

When war threatened the Netherlands, the Lugts together sent the top pieces of their impressive collection of drawings, prints, books, and paintings in six packages to Switzerland.

During the Second World War, the couple fled to the United States, where Wolfgang Stechow secured a temporary position for him lecturing at Oberlin College, Ohio.

After the war they returned to their home in The Hague by boat, accompanied by fifty chests of books, catalogs, journals, and reproductions, most of which he gave to the RKD.