Background: The resurgence of syphilis in men who have sex with men (MSM) has proved remarkably resilient in the face of innovative control and prevention interventions. Understanding the determinants of the current outbreaks has been restricted by the available data. Qualitative work is needed to understand individual and community experiences of syphilis and to help guide new prevention and control efforts. Methods: An exploratory study using semi-structured interviews with a convenience sample of MSM (n = 15), recently diagnosed with infectious syphilis, attending sexual health and HIV-outpatient services in Brighton, England. Results: Analysis focussed on men’s beliefs about syphilis, their experience of testing and being given a syphilis diagnosis, mediators of ‘risky’ sexual behaviour and disclosure to social and sexual contacts. Two beliefs — ‘syphilis is rare’ and ‘syphilis is dirty’ — dominated respondents’ accounts. These beliefs coloured every aspect of respondents’ clinical and social experience of syphilis, and impeded disclosure and partner notification. They also contributed to misconceptions about behaviours with increased syphilis transmission risk, the mechanics of disease acquisition, health-seeking behaviours and risk-reduction strategies. Conclusions: The apparent failure of syphilis control measures so far may be due to our limited understanding of MSM’s views and experience of STIs other than HIV. Syphilis prevention needs to tackle MSM’s widely held beliefs about sexual communication, risk behaviour and other STIs. The most useful health education interventions are likely to be those that build on MSM’s significant knowledge base and address both the current syphilis crisis and wider sexual health promotion goals.