The quality of the relationships between volunteers and paid staff can have far-reaching consequences for organizations that utilize volunteer programs to support service delivery. We utilize a mixed methods case study design to explore volunteer and staff perceptions of their mutual interactions within a large library system in the southeastern United States. We consider which areas of these interactions might be vulnerable to conflict. Our findings suggest that conflict is likely to arise due to communication problems, behavioral or attitudinal issues, perceptions of job vulnerability, divergent expectations, lack of trust, and workflow integration hurdles. We argue that to avoid these tensions and promote effective service delivery, staff members must have appropriate training and preparation to interact successfully with volunteers.VOLUNTEERS SERVE AS key sources of human capital for many organizations in the public and nonprofi t spheres, often working in conjunction with the paid staff in those organizations (Gidron 1985 ). Engaging volunteers requires investments of eff ort, time, training, and fi scal resources so that both organizations and volunteers benefi t. Nancy Macduff ( 2012 , 256) argues that "the relationship between volunteers and staff can infl uence the success or failure of a program … and the ability to make positive organizational changes." As such, a purposive volunteer-staff relationship is critical. Despite the importance of these working relationships, many organizations fall prey to the misperception that volunteers are a source of "free labor" (Handy and Mook 2011 ). Such organizations may inadequately invest in the management of these valuable human resources (Hager and Brudney 2004 ;Machin and Paine 2008 ). Too often, paid employees fi nd themselves inadvertently directing and supervising volunteer labor, rather than being trained and prepared to take on this role (Nesbit et al. 2016 ). Th is situation can be particularly challenging when organizations increase their use of volunteers, such as during times of fi scal constraint when increased reliance on volunteers is often utilized as a strategy to reduce personnel costs (Brudney