This paper is dedicated to four unpublished drawings relating to tomb monuments of the old Casa Tondi in Siena, which sheds new light on Sienese sculpture in the early 16th century. The first of these is a detailed project for the tomb monument of the rector Giovanni Battista Tondi, conserved in the atrium of the old hospital of Santa Maria della Scala. The signature on the sheet tells us that the monument can now be attributed to Lorenzo di Mariano, known as Marrina, and dated not long after the death of the deceased (10 April 1507).In Siena in the early decades of the 16th century the Tondi were an eminent family, three of whose members were rectors of Santa Maria della Scala. For this reason it is not easy to identify the protagonists of the other three drawings. Two of them show tombs that are still late 15th-century in style, drawn by artists who unfortunately remain anonymous. However, we can recognize the hand of the young Domenico Beccafumi in the final drawing, which shows the sketch of a monument that can almost be superimosed over the one designed by Marrina and therefore goes to increase the limited number of graphic works attributable to the early career of Mecarino. This work has the merit of attesting Beccafumi's early interest in sculpture, though raises questions concerning the identification of the gisant, the dating, and the artistic relations between Domenico and Lorenzo di Mariano.