His religious faith caused him some difficulties, therefore he came back to the Netherlands in 1674. He then lived in Deventer until 1679, when he was appointed Professor of Greek history and language at the University of Leiden. One year later, on 5 May 1680 he married Anna van Vredenburch from Rotterdam.

Gronovius is chiefly known as the editor of the Thesaurus antiquitatum Graecarum (1697-1702, in 13 volumes). He died,