Over the past two decades research has consistently found that bisexual people experience poorer mental health than their gay, lesbian or heterosexual counterparts. The reasons behind this high prevalence of poor mental health remain under-researched and largely unknown. In order to improve these outcomes, more research is critically needed with the aim of providing new knowledge upon which health care provision and policy development can be based. This article presents an analysis of the literature to date relating to bisexuality broadly and bisexual mental health specifically, with the aim of providing direction for future research projects.