We report the case of a 28-year-old female prostitute, intravenous drug user, seropositive for human immunodeficiency virus and with unusual manifestations of lues infection. The presence of plantar keratoderma, alopecia of the scalp, total loss of hair eyebrows and eyelashes with bilateral chorioretinitis is emphasised. Non-treponemal and treponemal tests for syphilis showed reactivity, but with abnormal serologic expression. The possible relationship between H.I.V. infection and the natural course of syphilis is discussed.