Since management strategies are guided by the assessment of the symptom experience, agreement between patients' and nurses' perceptions of symptoms is central to clinical management. In this study, acquired immune deficiency syndrome patients' perceptions of 41 human immunodeficiency virus-related signs and symptoms were compared in 207 pairs of ratings by patients (n = 207) and nurses (n = 103). Ten symptoms were reported by 50% or more of the patients. Mean patient intensity ratings for all signs and symptoms, with the exception of anxiety, were higher than nurse ratings. Using patients' ratings as the gold standard, chance-corrected estimates of sensitivity, specificity, positive predictive value, and negative predictive value of the nurses' ratings suggested that nurses' ratings poorly predicted patients' symptom experiences.