To study the prevalence, intensity, and quality of pain in patients with human immunodeficiency virus (HIV) infection and to evaluate factors influencing the different components of pain, a self-administered multidimensional pain questionnaire (Italian Pain Questionnaire [IPQ]) was administered to 153 HIV patients admitted to the Department of Infectious Diseases of a teaching hospital over a 7-month period. Ninety-three (60.8%) patients experienced pain for a total of 131 pain sites. The intensity and the nonsensorial components of pain were greater in ward patients compared to outpatients. In 70% of pain syndromes it was not possible to define the etiology at the time of the visit. Pain was observed more frequently in intravenous drug users (IDUs) (72.9%) compared to patients with other HIV modalities of transmission (50.6%) (p = 0.008). The mean value of sensory class was greater in patients who were not IDUs. Within IDUs group there was a predominance of descriptors of the affective class over the sensory class. The prevalence of pain is high in HIV-infected individuals. The different components of pain are influenced by the modality of transmission and the setting of care. The assessment of scores of different components of pain could help to select and monitor appropriate interventions in pain control.