Because effects of cigarette smoking on health-related quality of life (HRQL) have not been well described, we carried out a cross-sectional assessment of HRQL using the Medical Outcomes Survey Scale adapted for patients with human immunodeficiency virus (MOS-HIV questionnaire) in 585 HIV-infected homosexual/bisexual men, injection drug users, and female partners enrolled in a multicenter, prospective study of the pulmonary complications of HIV infection. Mean scores for the following dimensions of HRQL were calculated: general health perception, quality of life, physical functioning, bodily pain, social functioning, role functioning, energy, cognitive functioning, and depression. A multivariate model was used to determine the impact on HRQL of the following factors: smoking, CD4 loss, acquired immune deficiency syndrome (AIDS) diagnoses, number of symptoms, study site, education, injection drug use, gender, and age. Current smoking was independently associated with lower scores for general health perception, physical functioning, bodily pain, energy, role functioning, and cognitive functioning (all with p < 0.05). We conclude that patients with HIV infection who smoke have poorer HRQL than nonsmokers. These results support the use of smoking cessation strategies for HIV-infected persons who smoke cigarettes.