Bacillary angiomatosis is a systemic disease caused by Bartonella (B.) henselae and B. quintana. Today it is a rare disease that occurs predominantly in patients with poor adherence to antiretroviral therapy or with late diagnosis of human immunodeficiency virus (HIV). We report on the case of a 40-year-old Caucasian female with HIV-1 and hepatitis B virus (HBV) co-infection diagnosed 17 years ago. She presented to the emergency department with an erythematous, painless nodule located on the left naso-genian fold. In the next few weeks the disease disseminated to the oral and left tarsal mucosa and to the palm of the left hand. The histopathological findings were suggestive of bacillary angiomatosis which was confirmed by polymerase chain reaction (PCR). The patient was treated with clarithromycin 500 mg bid per os for 3 months, with complete remission of the mucocutaneous lesions. Bacillary angiomatosis is a potentially fatal disease. Early diagnosis and treatment are critical in reducing the morbidity and mortality associated with it.