On 7 th November 2007 the UK Critical Sexology seminar series (www.criticalsexology.org.uk) hosted a one day event focusing on international perspectives on bisexuality. This seminar drew together academics and activists from several different countries and disciplinary approaches, most of whom were informed, to some extent, by queer theory. As part of the day we chaired a discussion considering the potentials and pitfalls of bringing together queer theory and bisexuality research, and the links between these issues and the agendas of queer/bi activism. This article reports on the main themes emerging from this debate and discusses them in relation to wider writing on queer theory and bisexuality. One specific tension that emerged was the usage of the word 'queer' and what this meant to participants. Another was the tension between a bi identity politics agenda of giving a voice to a largely silenced sexuality and a queer agenda of challenging dichotomous understandings of sexuality and gender. It is clear, from the discussion and other work in this area, that rather than polarising this as an either/or debate, it is more productive to consider the possibilities of both/and conceptualisations and to view this as a creative tension. In this paper we explore these possibilities in depth, considering the way queer theory can open up multiple and fluid sexual, gendered and self experiences, whilst remembering the lived experience many have of fixed identities and the importance of these for achieving visibility. We also explore the links between academic research and theory, and real-world practice.