A widespread kind of parallelism is a relation between sections of text such that each resembles the other in linguistic form, or in lexical meaning, or in both form and meaning. In poetry, this kind of parallelism can be systematic, and when it is, it holds between two adjacent sections. The new claim of this article is that these sections are short enough for the whole parallel pair to be held in working memory (in the episodic buffer). Parallelism thus shares a property with the other added forms of poetry – meter, rhyme and alliteration – that it holds over material which can be held as a whole section (such as line or couplet) in working memory. I conclude by suggesting that processing the parallel pair in working memory brings advantages to the poetry: an emotional effect from contrastive valence, an epistemic effect from the fluency heuristic, and the production of metaphorical meaning.