The Nag Hammadi texts have earlier been compared with Manichaean texts, but always resting on the assumption that the former influenced the latter. However, since Manichaeans existed in Egypt for more than a century before the Nag Hammadi codices were produced, the possibility that Manichaeism influenced Nag Hammadi texts cannot be ruled out. We know, at least, that the two clusters of texts share (1) Egyptian provenance, (2) the Coptic language, (3) Christian background, and (4) that their extant manuscripts are from the fourth or fifth centuries. I will show that mutual influences can, in fact, be detected in Nag Hammadi and Manichaean sources. But what is the nature of these literary connections? Sympathetic, polemic, or something else?