PrEP is an effective daily prevention medicine used to reduce risks of HIV infections. Previous research has pointed out the intention–behavior gap on PrEP uptake among gay men. The current study built on research examining how the integrative model of behavioral prediction (IMBP) factors influences PrEP uptake among gay men to explore how actual control variables, namely skills and environmental constraints, moderated the intention–behavior relationship. We used results from formative interviews to construct a survey and collected data from 420 gay men. Results showed several factors that were associated with PrEP uptake among gay men. Specifically, the lack of access to an LGBTQ-friendly healthcare provider(s) and lack of English fluency had significant main effects on PrEP uptake behavior, while lack of access to a healthcare provider and lack of healthcare system knowledge were significant moderators of the intention–behavior relationship. This study advances our understanding of the IMBP and offers practical implications for PrEP promotion. Limitations and suggestions for future studies are discussed.