István Csűry was one of the most educated people in Hungarian library affairs, with an extensive professional experience, sensitivity towards problems, and also an initiating worker with an unprecedented receptivity to new endeavors. István Csűry’s first and only workplace was the University Library of Debrecen, where after about a decade of working as a librarian, served as director from 1956 until his death, and elevated the institution to a second national library. The study reflects on the library areas where István Csűry has achieved essentially new results.