Pre-exposure prophylaxis (PrEP) with Truvada has emerged as an increasingly common approach to HIV prevention among gay, bisexual, and other men who have sex with men. This study examined generational differences and similarities in narrative accounts of PrEP among a diverse sample of 89 gay and bisexual men in the U.S. Over 50% of men in the older (52-59 years) and younger (18-25 years) generations endorsed positive views, compared with 32% of men in the middle (34-41 years) generation. Men in the middle cohort expressed the most negative (21%) and ambivalent (47%) views of PrEP. Thematic analysis of men's narratives revealed three central stories about the perceived impact of PrEP: (1) PrEP has a positive impact on public health by preventing HIV transmission (endorsed more frequently by men in the older and younger cohorts); (2) PrEP has a positive effect on gay and bisexual men's sexual culture by decreasing anxiety and making sex more enjoyable (endorsed more frequently by men in the middle and younger cohorts); and (3) PrEP has a negative impact on public health and sexual culture by increasing condomless, multi-partner sex (endorsed more frequently by men in the middle and younger cohorts). Results are discussed in terms of the significance of generation cohort in meanings of sexual health and culture and implications for public health approaches to PrEP promotion among gay and bisexual men.