© 2022, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.Despite efficacy in HIV prevention, Pre-exposure Prophylaxis (PrEP) is underutilized in the US, especially among populations at highest risk. PrEP-related stigma may play a role. We developed measures of PrEP-related stigma dimensions and PrEP adherence. We administered them to current PrEP users. We hypothesized that PrEP-related stigma would negatively impact PrEP adherence. Questionnaire measures were developed using data from previous qualitative work and existing validated HIV-related stigma measures. The resultant survey was administered to current PrEP users from two Birmingham, Alabama PrEP clinics. Plasma tenofovir disoproxil fumarate levels were collected to measure PrEP adherence. Exploratory factor analyses were performed to determine the factor structure of each PrEP-related stigma dimension (internalized, perceived, experienced, anticipated, disclosure concerns). Separate binary logistic (or linear) regressions were performed to assess associations between PrEP-related stigma dimensions and adherence (treatment adherence self-efficacy, self-reported adherence, and plasma tenofovir levels), adjusting for education, race, and time on PrEP. In 2018, 100 participants completed the survey, with 91 identifying as male and 66 as white. Only internalized stigma was associated with lower self-reported PrEP adherence. Exploratory mediation analyses suggested that the association between all stigma dimensions and self-reported PrEP adherence is mediated by PrEP adherence self-efficacy. No associations were found between any PrEP-related stigma measures and plasma tenofovir levels. Internalized PrEP stigma may reduce PrEP adherence, possibly by reducing PrEP adherence self-efficacy among experienced PrEP users. Further investigation of how stigma dimensions affect PrEP adherence in populations at risk for HIV may shed light on drivers of PrEP underutilization.