We assessed the frequency and variability of rheumatologic manifestations in 2 populations with similar risk factors for human immunodeficiency virus (HIV) infection, of which only one was affected. We studied 2 populations at risk for HIV infection (homosexual and intravenous drug users). Group A: 89 individuals carried the virus; and Group B: 80 individuals were HIV negative. In Group A (HIV+) 66.1% had rheumatic manifestations including arthralgias, Reiter's syndrome, arthritis, enthesitis, psoriatic arthritis, Sjögren's syndrome, myopathy, septic arthritis, and lupus-like illness. In contrast, in Group B (HIV-) only 2 had arthralgias, 2 Reiter's syndrome, and 1 rheumatoid arthritis. In summary, rheumatic complaints are common in patients with HIV, and HIV positivity confers an increased susceptibility in populations with similar risk factors for HIV infection.