Bartonella is an infrequent yet important pathogen in immunocompromised patients. Bartonella infections can cause serious morbidity and mortality in people living with human immunodeficiency virus (PLWH), particularly those with advanced immunosuppression. The  prevalence of  clinically evident Bartonella infections among PLWH is relatively low. Here, we reported a bacillary angiomatosis (BA) case in a homeless HIV-positive patient. A 31-year-old man with acquired immunodeficiency syndrome (AIDS) and advanced immunosuppression, who had discontinued antiretroviral therapy (ART) one year ago, referred to the hospital. At the admission, he had nausea, vomiting, anorexia, weight loss, occasional sputum cough, subjective fevers, and multiple skin lesions. Lesions’ biopsies were non-diagnostic for routine bacterial, tuberculosis, and fungal infection. However, the diagnosis of Bartonella quintana was confirmed by serum polymerase chain reaction (PCR). After receiving a long course of antibiotic therapy, skin lesions resolved. The patient had a favorable outcome with supportive care and continuation of ART and doxycycline. While easily treated, an infection due to Bartonella may be clinically unrecognized, if skin lesions are absent or overlooked, and microbiologically unrecognized, if appropriate protocols are not followed. Because the fever caused by Bartonella infection is easily treated, it is essential that suspected clinical signs of Bartonella infection in immunocompromised hosts should be reported to the microbiology laboratory. Bartonella quintana infection can result in a broad range of often non-specific clinical manifestations; therefore, case patients must be evaluated for suspected bacteremia, and clinical wariness is required for diagnosis.