This work examines certain aspects of the reactions to Ludovico Castelvetro’s work in early seventeenth century culture. Certain pages from Alessandro Tassoni from his letters, Pensieri and his poetry notes are first examined to analyse the take up to the commentary on Aristotle’s Poetics set out by Castelvetro. Significant comparisons have been carried out with Tasso’s position on one hand and that of Benedetto Fioretti on the other to the same purpose. In the second part, the presence of Castelvetro as critic and adversary of Caro are analysed, elements which were made opportune use of in the debates centring around Giovan Battista Marino. Certain episodes relating to Ferrante Carli and, above all, Tomaso Stigliani have been reinterpreted making use, in relation to the latter, of a number of unpublished works.