Multiple authorities have recommended that human immunodeficiency virus (HIV) testing should be performed only with consent of the patient. After institution of a policy requiring written consent for testing patients and employees after blood/body fluid exposures, we prospectively studied incidents in which employees were exposed to the blood or body secretions of patients to determine the rate at which HIV testing could be performed under these circumstances. Two hundred four employees suffered an exposure. In 184/204 (90%) of incidents, the index patient was known. HIV testing was performed for 125/184 patients (68%). Patient consent was refused in one case, but consent could not be obtained from an additional 58/184 (32%) patients because of various logistical reasons. We conclude that a policy requiring informed consent for HIV testing of a patient after exposure of an employee to blood or body fluids of the patient results in an unacceptably low rate of testing and that an alternative approach must be developed.