This paper examines a 9th-century Arabic text of genethlialogical astrology, arguing that while it presents itself as heir to a Greek science deriving from India, it is also a testament to the pervasive role played by Sasanian intellectual culture in the 8th- to 10th-century Greek-Arabic translation movement. After a description of the astrological text and its manuscripts, I turn to its technical vocabulary, focusing in particular on what its use of a Middle Persian technical term betrays about the text’s origins and the intellectual tradition in which it is to be situated. Finally, I argue that the tension between the text’s self-presentation as part of the ancient Greek astrological tradition and its Persian vocabulary can be resolved by considering how the text promotes itself: as a gateway to true knowledge through ancient science.