The Hittite ritual for the Ancient Gods (CTH 446) is one of the most interesting and complex in the Hittite ritual corpus. It describes a series of ritual procedures and recitations to be performed over two days with the goal of cleansing a house contaminated by impurity resulting from bloodshed. Summoned for the task are the Ancient Gods, Netherworld deities of the Hurrian-Hittite tradition. The present study provides an updated critical edition of this remarkable ritual, which is complemented with philological notes and commentary. Additionally, the volume investigates the nature and origins of the composition against the broader background of the Hittite ritual corpus.