This article is focused on the figure of painter Giovanni Battista Paggi (Genova 1554-1627), whose artistic culture between Florence and Genova made him a key figure in the process of naturalistic renovation of late Counter-Reformistic art. First we will examine in depth the relations between Paggi and florentine nobleman Niccolo di Sinibaldo Gaddi, who was as a sort of 'talent scout' for the painter in the Florence. We will then propose a new acquisition to the catalog of Paggi: the important panel representing the "Effusio Sanguinis" in the refectory of San Niccolo in Prato, and finally we'll assume, according to a list of goods owned by Paggi, that a female portrait attributed to him in the Pinacoteca Musa of Sassari is indeed the portrait of her daughter Maria Caterina.