The collaborative writing of free verse poetry is a rare endeavour in any country but perhaps particularly so in New Zealand. The field of haikai literature, however, offers frequent examples of collaboration, through various forms of renga, and its influence on poets who collaborate has been significant. Following the example of Octavio Paz, this paper will consider whether collaboration might mitigate against ‘the myth of the unique author’, the single and authoritative signature with which 20th-century theorists such as Barthes, Foucault and Derrida found so much fault, and which Paz tried to dispel through collaboration. The paper will consider examples of co-authored poetry published in New Zealand, in particular those involving Jenny Powell-Chalmers, who has been New Zealand’s most active collaborator in free verse. In discussing collaborative poetry, particular attention will be paid to voice and heteroglossia, including its social aspect, and with reference to Bakhtin’s stylistics of the novel. As well as analysing collaborative poems for the effects of voice achieved, this paper will try to suggest why writing collaborative poetry is productive and has potential for invigorating creative practice.