Articular manifestations are a frequent but often underdiagnosed manifestation in patients infected with the human immunodeficiency virus (HIV). We present a 7-year-old HIV-infected malnourished girl who presented with recurrent joint pain and effusion in the left knee joint. Her antistreptolysin O, dsDNA, antinuclear antibody and rheumatoid arthritis factor were negative. She responded to antiretroviral therapy.