Wasting remains a significant condition of human immunodeficiency virus (HIV) infection despite antiretroviral treatment. Early identification requires the measurement of various body composition parameters, particularly body cell mass (BCM). Anthropometry may provide some useful information. Cost and complexity issues make many body composition techniques unsuitable for the clinical setting. Bioelectrical impedance analysis (BIA) may be the best method available to caregivers for monitoring serial changes in BCM over time and for determining the occurrence of wasting. It is not useful, however, for detecting body composition changes in patients with fat redistribution syndromes. Portability, low cost, ease of use, and patient acceptance make anthropometry and BIA ideally suited for the clinical setting.