The book of Revelation includes more references to the Hebrew Scriptures than any other NT book. Even the sheer volume of scriptural references in the book of Revelation seems to suggest that the study of scriptural references is fundamental to understanding the book, as scholars have recognised for some time. Unlike the prophetic books, scholars have not given significant attention to the Psalms, although they do recognise the presence of many allusions to the Psalms. Through in-depth examination of the use of Psalms in Revelation this thesis demonstrates how significantly the Psalms influenced on the composition of the book of Revelation and offers a fresh insight of the structure and theology of the book. Part I (chapters 2–3) offers the background of this study. Chapter 2 discusses the use of Psalms in Second Temple Judaism, focusing on how the book of Psalms was employed in the Dead Sea Scrolls and the characteristics of the Greek translation of the Hebrew Psalms. Chapter 3 considers the significance of the Psalms for the early Christian communities. The Syriac version of the Psalms and the use of Psalms in the NT provide significant data/evidence for its use in early Christianity. Part II (chapters 4–7) examines all detectable cases of Psalms in Revelation. The cases are divided into four categories: strong allusion (chapter 4), probable allusion (chapter 5), possible allusion (chapter 6) and influence (chapter 7). In total, thirty-seven cases are considered: eight for strong allusion, seven for probable, nine for possible, and twelve for influence. As a conclusion of the study, Part III (chapter 8) presents the significance of the Psalms in the book of Revelation. The chapter sheds light on liturgical use of Psalms in the book of Revelation and in relevance with the Psalms some theological themes important for understanding the book will be set forth.