Despite objections that can be raised against the way ancient rhetorical categories are applied to the New Testament letters, an analysis of Ephesians which labels 6:10-20 as peroratio proves illuminating. Most discussions of this pericope have simply treated it as the concluding element of the letter's paraenesis, while noting its apparent change of imagery and mood. It is argued here that, on a rhetorical analysis, Ephesians 6:10-20 contains the major elements expected of a peroratio by the ancient rhetoricians and also has features in common with ancient accounts of speeches of generals before battle. Once the pericope is recognized as a peroratio, greater justice can be done to its links with the whole of the letter, fresh light is shed on the dispute about the reference of the various pieces of armour, and the concluding depiction of Paul's imprisonment falls into place. In particular such an analysis enables a clearer evaluation of the effectiveness of the pericope's imagery and exhortation as part of the writer's overall strategy of persuasion.