We estimated the prevalence and factors associated with the use of a dedicated HIV prevention, care, and treatment service for female sex workers (FSWs) in Kampala, Uganda. Between October 2017 to January 2018, we conducted a cross-sectional study among FSWs at a dedicated clinic. We defined use as the use of the HIV prevention, care, and treatment services by FSWs at least once within the past six months. We used the log-binomial model to determine the factors associated with use of clinic services. Eight hundred and seventy-four women were included in the analysis. The overall prevalence of use of clinic services was 81%. At adjusted analysis, use of clinic services was independently associated with being HIV positive and being treated for STIs in the past three months. The prevalence of use of clinic services was high. Dedicated services for FSWs are required to support their use of HIV and STI care.