Malnutrition is a frequent complication of human immunodeficiency virus (HIV) infection and is associated with a poor prognosis. To compare different measures of nutritional status in HIV-infected patients, we prospectively studied 88 outpatients seen at a Paris AIDS outpatient clinic for routine follow-up examinations. Nutritional status was assessed according to body weight loss (BWL, 4 classes), anthropometry, bioelectric impedance analysis (BIA), and subjective global assessment of nutritional status (SGA). Malnutrition was diagnosed in 22.4% of subjects using SGA, and 37.1% by BWL. SGA rapidly detected a worsening of nutritional status, while BWL detected malnutrition at an earlier stage. A good correlation was found between SGA class and body composition assessed by anthropometry and BIA. Deteriorating nutritional status diagnosed by SGA correlated with the CDC HIV disease class. SGA, a simple nutritional assessment, can serve as a basis for prescribing artificial nutrition, while BWL detects malnutrition at an earlier stage.