Common indices for the assessment of nutritional status take height into account. Elderly individuals are frequently unable to assume the position needed for this measurement. Therefore, equations have been developed for predicting height in elderly American Whites, American Blacks, and Mexican Americans using knee height as a predictor. These equations may not be applicable for the elderly in other populations. A sample of 736 individuals was studied (186 males, 550 females) with a mean age of 74.7 ± 8 years. Height and knee height (without shoes) were measured in millimeters. Multiple regression and cross-validation was performed. The correlation between knee height and standing height was similar in women (r = 0.86; P < 0.0001) and men (r = 0.83; P < 0.0001). The equations obtained were as follows: men (height in cm) = 52.6 + (2.17 × knee height in cm) and women (height in cm) = 73.7 + (1.99 × knee height in cm) − (0.23 × age in years). Cross-validation showed that the pure error was less than the root mean square error (RMSE) in both sexes. Mean heights, based on the equations of Chumlea et al. (1998) for Mexican Americans significantly differ from the reference values for females and males. Therefore, the equations developed by Chumlea et al. (1998) for elderly Mexican Americans do not appear to be applicable for elderly Mexicans. Am. J. Hum. Biol. 14:351–355, 2002. © 2002 Wiley-Liss, Inc.