The Lectionarium Placentinum is contained in four parchment manuscripts, Piacenza, Biblioteca Capitolare codices 60-63, which have been dated to the second half of the twelfth century and form part of a collection of liturgical manuscripts produced in that period. The lectionary is divided in two parts, each consisting of two manuscripts: the Temporale contained in Pia 61-60, and the Sanctorale in Pia 62- 63. The four manuscripts contain around 250 Gospel incipits and 700 texts. While the majority of the texts in the Temporale are sermons written by Ambrose of Milan, Augustine of Hippo and the popes Leo the Great and Gregory the Great, the major part of the texts in the Sanctorale are anonymous saints’ vitae and passion stories. Like the Temporale edition, the Sanctorale edition is divided in two volumes, the first including an introduction to hagiography, a description of the manuscripts and their contents, and the second an inventory, bibliography and indices. The first part of the edition covers the period from Stephen protomartyr (December 26) to Bishop Germanus (July 31) and the second part the period from Peter in Chains (August 1) to Victoria (December 23). Both parts moreover contain an appropriate commune sanctorum section. The lectionary provides information on the reception and liturgical use of texts of the patristic and early medieval church fathers in the twelfth century and presents an instrument for further studies to scholars in various fields of research. The edition might be a useful tool to liturgists investigating the contents and structure of the medieval office as well as to scholars investigating and/or analysing the Latin language, liturgical literature, biblical exegesis and commentaries, theology, hagiography, history of ideas and mentality, as well as Latin translations of Greek texts.