This article argues that 2 Cor 3:7–18 was neither composed by Paul nor inserted by him at its present location in 2 Corinthians—that the passage is, in fact, a later, non-Pauline interpolation. More specifically, it proposes (a) that the relation of vv. 7–18 to their context, both immediate and larger, points to the secondary insertion of the passage between 2 Cor 3:6 and 2 Cor 4:1, (b) that distinctive vocabulary in the verses suggests composition by someone other than Paul, and (c) that apparent verbal and/or conceptual links between vv. 7–18 and their immediate context, however, suggest composition of the verses (by someone other than Paul) precisely for the purpose of insertion at their present location in 2 Corinthians. Finally, the article offers a possible scenario explaining why the interpolation appears where it does in 2 Corinthians.