This study explored familiarity with, attitudes toward, uptake and discontinuation of PrEP (Pre-exposure prophylaxis) among a national probability sample of gay and bisexual men. PrEP is one of the most effective biomedical HIV prevention strategies; however, use among gay and bisexual men remains low within the United States. This study used a national probability sample of gay and bisexual men from three age cohorts of men (18-25, 34-41, and 52-59 years at wave 1) who completed three annual surveys between March 2016 and March 2018 (N at wave 1 = 624). Recruitment occurred through a Gallup dual-frame sampling procedure; results for this study came from eligible individuals who consented to be part of the self-administered online or mailed survey questionnaire. We used descriptive data with sampling weights to understand trends in PrEP familiarity, PrEP attitudes and PrEP use across all three time points. Next, PrEP uptake and discontinuation were assessed among men completing all three surveys and who remained eligible for PrEP at all three time points (N = 181). PrEP familiarity increased considerably between 2016 and 2018 among those eligible for PrEP (from 59.8% from wave 1 to 92.0% at wave 3). Favorable attitudes toward PrEP increased more modestly (from 68.3% at wave 1 to 72.7% at wave 3). While PrEP use increased by 90% between the two time points (from 4.1% in 2016 to 7.8% in 2018), this represented a small percentage of overall uptake among eligible participants across time (6.6%). Among respondents who reported PrEP use at wave 1 or wave 2, 33.3% subsequently discontinued PrEP use at a later wave. Findings indicate modest increases in PrEP use between 2016 and 2018 in a national probability sample of sexually-active gay and bisexual men. PrEP discontinuation was high and suggests the need for further research into gay and bisexual men's PrEP discontinuation and persistence.