The epitaph on De Monte's tomb describes him as an "excellent patron of the good arts". Del Monte was a perceptive supporter of the arts and sciences - he was the first recorded owner of the Portland Vase, and his Palazzo Madama household was one of the most important intellectual salons in Rome. At his death his art collection contained more than six hundred paintings, and his support of the young Caravaggio has given provenance to several of that artist's early works.