We present the case of an HIV-positive patient who developed polymorphous lesions in which the evidence in the skin biopsy corresponds to the diagnosis of bacillary angiomatosis, and further tests proved the pathological agent involved in this case is not the usual Bartonella species, B. henselae and B. quintana, but B. elizabethae. As far as we know, this is the first case of bacillary angiomatosis secondary to this etiological agent.