We describe a case in which a patient infected with the human immunodeficiency virus (HIV) with high plasma viral titers underwent an arthroscopic partial meniscectomy allowing US the opportunity to measure the HIV titer of serial aliquots of the arthroscopic effluent using the polymerase chain reaction. Two out of six aliquots were found to be HIV positive with 598 and 486 vital copies per milliliter noted. The plasma vital load at the time of surgery was 149,000 copies per milliliter, whereas the prearthroscopy synovial fluid failed to show any detectable virus. This is the first report to our knowledge of HIV detected in an arthroscopic effluent. The clinical implications for the arthroscopist are also discussed.