Geosocial-networking smartphone applications are commonly used by gay, bisexual, and other men who have sex with men (MSM) to meet sexual partners. The purpose of the current study was to evaluate awareness of and willingness to use pre-exposure prophylaxis (PrEP) among MSM who use geosocial-networking smartphone applications residing in New York City. Recruitment utilizing broadcast advertisements on a popular smartphone application for MSM yielded a sample of 152 HIV-uninfected MSM. Multivariable models were used to assess demographic and behavioral correlates of awareness of and willingness to use PrEP. Most participants (85.5 %) had heard about PrEP but few (9.2 %) reported current use. Unwillingness to use PrEP was associated with concerns about side effects (PR = 0.303; 95 % CI 0.130, 0.708; p = 0.006). Given that more than half (57.6 %) of participants were willing to use PrEP, future research is needed to elucidate both individual and structural barriers to PrEP use among MSM.