This guide identifies resources on patristics and early church history found in Pius XII Memorial Library. The guide is intended for use by both beginning or advanced graduate students and faculty. It includes both English language and foreign language titles and includes resources in Classical Studies as an ancillary discipline for study of the early church. The annotations are intended to provide basic information or to supplement information found in the printed sources listed under Research Guides/Bibliographies. To facilitate access to the information in these printed sources, cross references, including page and/or entry numbers, have been included in most of the annotations.