Evaluation has become expected within the nonprofit sector, including HIV prevention service delivery through community-based organizations (CBOs). While staff and directors at CBOs may acknowledge the potential contribution of evaluation data to the improvement of agency services, the results of evaluation are often used to demonstrate fiscal prudence, efficiency, and accountability to funders and the public, rather than to produce information for the organization's benefit. We conducted 22 in-depth, semi-structured interviews with service providers from four agencies implementing the same evidence-based HIV prevention intervention. We use the lens of "audit culture" to understand how the evaluation and accountability mandates of evidence-based program implementation within HIV prevention service provision affect provider-client relations, staff members' daily work, and organizational focus in natural settings, or contexts without continuous support and implementation monitoring. We conclude with recommendations for improving the use and methods of evaluation within HIV prevention service delivery.