Syphilis has been resurgent in Australian cities for the last decade. The varied presentation of this infection requires the physician to consider syphilis in the differential diagnosis of a broad range of conditions. Most cases are in men who have sex with men, young people in remote Aboriginal communities, or travellers from high-prevalence countries. The diagnosis and staging of syphilis require a sexual history, physical examination and interpretation of serological and microbiological findings. Penicillin remains the mainstay of effective treatment and has been used successfully for over 65 years. Treatment failure is rare, whereas reinfection is common. The interaction of syphilis and human immunodeficiency virus is complex, but standard therapy remains curative, and lumbar puncture is rarely required. Regular testing of high-risk individuals, contact tracing with empirical treatment and serological follow up are important components of syphilis control.