This article discusses the definition of Ophite Gnosticism, its relationship to Sethian Gnosticism, and argues that Eugnostos, Soph. Jes. Chr., Orig. World, Hyp. Arch. and Ap. John not only have important links with each other but also draw essentially on the mythology the heresiologists called that of the Ophites. Before the Nag Hammadi findings, Ophite Gnosticism was often seen as an important and early form of Gnosticism, rooted in Jewish soil, and only secondarily Christianized. Today, not only are similar claims made of Sethian Gnosticism, but also some of the above-mentioned texts are classified as Sethian. In many recent studies, the Ophite mythology is connected with Sethian Gnosticism, even though the exact relationship between these two forms of Gnosticism has remained unclear. It is argued here that the Sethian Gnostic authors drew on earlier forms of Gnosticism, especially on the Ophite mythology, in composing some of the central Sethian texts.