OBJECTIVE: In this prospective study, we assessed nutritional and immunologic risk factors for infectious complications and deaths related to infection in elderly patients undergoing major elective surgery. METHODS: Seventy patients 60 y or older were enrolled in this study.. The preoperative variables analyzed were body mass index, body mass index knee height, triceps skinfold, subscapular skinfold, mid-arm muscle circumference, mid-arm muscle area, albumin, transferrin, prealbumin, and retinol-binding protein levels, immunoglobulins G, A, and M, C3, and C4 levels, total lymphocyte counts, and the occurrence of delayed hypersensitivity reactions (multitest). RESULTS: Abnormally low levels of prealbumin (P = 0.004), retinol-binding protein (P = 0.05), and transferrin (P = 0.04) were related to infectious complications. Prealbumin levels (P = 0.02) and lymphocyte counts below 1500 cells/mm(3) (P = 0.04) were associated with mortality secondary to infection. Univariate regression analysis showed that levels of prealbumin (P = 0.02, odds ratio = 13.3, 95% confidence limits = 1.6, 110.9), retinol-binding protein (P = 0.03; odds ratio = 4.8, 95% confidence. limits = 1.2, 19.3), and transferrin (P = 0.03; odds ratio = 4.2, 95% confidence limit = 1.2, 15.6) were associated with infectious complications. Multivariate analysis associated only prealbumin levels with infectious complications (P = 0.02, odds ratio = 13.3, 95% confidence limit = 1.6, 110.9). Regression analysis provided no conclusion regarding mortality because of the small number of deaths recorded. CONCLUSIONS: In patients with a good cardiac index (Goldman I and II) who underwent major elective surgery, prealbumin protein, retinol-binding protein, and transferrin levels below normal values represented a significant risk for postoperative infectious complications. Lymphocyte counts lower than 1500/m(3) and abnormal prealbumin values were associated with postoperative mortality secondary to. infection. The anthropometric variables evaluated did not predict postoperative infectious complications and mortality.194321326