Objectives To determine the syphilis infection and risk factors among the male outpatients in sexually transmitted disease （STD） clinics in Taizhou， and to provide a scientific evidence for the development of comprehensive prevention and intervention strategies for syphilis.

Methods A questionnaire survey and serological testing were conducted among the male STD outpatients in the hospitals designated for STD treatment in Jiaojiang， Linhai， Luqiao and Sanmen in Taizhou. Logistic regression analysis was used to determine the risk factors associated with syphilis infection.

Results A total of 16 400 male STD outpatients were investigated， with a syphilis infection rate of 2.10%. Multivariate analysis showed that aged over 60， non-local household registration， engaging in sexual activity with commercial sex workers in the past three months， having two or more sexual partners in the past three months， engaging in anal sex with heterosexual partners， co-infection with human immunodeficiency virus （HIV）， and co-infection with hepatitis C virus （HCV） were significantly associated with a higher syphilis infection rate （all P<0.05）. Knowledge of HIV/AIDS， a history of chlamydia infection in the past year， and a history of genital wart infection were significantly associated with a lower syphilis infection rate （all P<0.05）.

Conclusion Syphilis infection among the male STD outpatients in Taizhou remained lower， compared with the national average level. Targeted comprehensive prevention and control strategies should be implemented based on relevant risk factors. Screening and prevention interventions should be prioritized for the individuals with non-local household registration， at-risk sexual behavior， and co-infection with HCV and HIV. Strengthening the collaborative efforts is also recommended for joint prevention and control of HIV/AIDS and syphilis.