Hospice volunteers play an essential role in the primary care network for end of life. The purpose of this review was to examine the evidence on hospice volunteers published between 2002 and July 2012. An electronic search of PubMed, CINAHL and PsychINFO using controlled vocabulary, and a reference scan, yielded 54 studies focusing on hospice volunteers. Studies were primarily descriptive using quantitative, qualitative and mixed methods. Findings from studies were grouped thematically into descriptions of the work of hospice volunteers; recruitment, preparation and retention of hospice volunteers; and perspectives and outcomes of the volunteer role. A substantial body of evidence exists describing the roles, stresses and rewards of hospice volunteering. Less is known about how to adequately recruit, prepare and retain volunteers. A small but intriguing body of evidence exists around volunteers' contributions to family satisfaction and patient longevity. Although the evidence around hospice volunteers continues to grow, there is an urgent need for further research. Findings indicate that volunteers make important contributions to high quality end of life care. However, more focused research attention is required to better understand how to maximize this contribution while providing better support for volunteers.