For marginalized populations, county health departments may be important PrEP access points; however, there are little data on successful PrEP programs at these venues outside of incentivized demonstration projects. Therefore, we implemented an open-access, free PrEP clinic at a county health department in Atlanta, GA to promote PrEP uptake among high-risk clients. The Fulton County Board of Health PrEP clinic launched in October 2015, and eligible clients who expressed interest initiated PrEP and attended follow-up visits per CDC guidelines. Clients engaged in quarterly follow-up and seen within the last 6 months were defined as "persistent", whereas clients with a lapse in follow-up of > 6 months were defined as "not persistent." Factors associated with PrEP persistence were assessed with unadjusted odds ratios. Between October 2015 and June 2017, 399 clients were screened for PrEP, almost all were eligible [392/399 (98%)]; however, 158/392 (40%) did not return to start PrEP after screening. Of 234 patients, 216 (92%) received a prescription for PrEP. As of June 2017, only 69/216 (32%) clients remained persistent in PrEP care, and the only evaluated factor significantly associated with PrEP persistence was age ≥ 30 years (OR 1.86, 95% CI 1.02, 3.42). Implementation of PrEP in the county health department setting is feasible; however, we have identified significant challenges with PrEP uptake and persistence in our setting. Further research is needed to fully understand mediators of PrEP persistence and inform interventions to optimize health department-based PrEP services.