The purpose of this study is to analyse the complex development of the key as an unusual attribute of Lucina in Renaissance iconography, which appears to have been influenced by several semantic fields and emerged as a visible phenomenon of a deeper cultural dynamic. The works of artists such as Jacopo Zucchi, Lorenzo Lotto, and Raphael, together with the mythographic treatises of antiquarian scholars such as Lilio Gregorio Giraldi, Giovanni Pierio Valeriano, Vincenzo Cartari and Baccio Baldini, will be examined for the purpose of retracing all aspects of this evolutionary path. What emerges is new material concerning the different perspectives on Lucina during the sixteenth century, including new symbolic readings derived from the philological and textual interpretations that influenced the iconographic building method of that time