The clinical manifestations of syphilis are variable in appearance and have been described for centuries. The disease has been arbitrarily divided mainly into three stages. Uncommon presentations of syphilis in adults include (a) primary syphilis-atypical forms of chancre vary in size, shape, morphology, and color. Small ulcus durum is single or multiple, grouped, or herpetiform. Giant necrotic and phagedenic chancres are resolved with scar formation. In intratriginous areas, ulcus durum is rhagadiform, linear, "rocket type," or bilateral. (b) Secondary syphilids include macular (roseolas, leukomelanoderma), papular (small miliar or lichenoid, or with large size-lenticular or nummular), papulosquamous, syphilis cornee, psoriasiform, annular en cockade, nodular, condylomata lata, malignant syphilis, and others; there are also mucosal lesions, loss of the hairs, and alteration of the nails. (c) Tertiary syphilis occurs decades after infection in three main forms: gummatous, cardiovascular, and neurosyphilis (asymptomatic, meningeal, meningovascular, and parenchymatous-such as general paresis or tabes dorsalis). Early recognition of the clinical manifestations of syphilis is important for the start of treatment, recovery of patients, and the prevention of the spread of disease.