Discriminant functions that used all 19 bones of each hand found little difference in the ability of the length measurements of the left and right hands to classify skeletons correctly by sex. When analyzed by bone row, however, the left hand correctly classified skeletons better than either the right hand or the right foot, with more rows exceeding the 80-percent correct classification rate. None of the bone rows in the foot exceeded the 80 percent classification threshold. The left hand also produced the best discriminant functions based on stepwise selected variables. Most of the bone measures used in previous studies of sex determination from the hands and feet have involved measures of breadth or height rather than length; however, base width, base height, head width, head height, and midshaft diameters are all measures that may continue to change after puberty, potentially increasing the error associated with these measures. Length, on the other hand, may change slightly at the proximal and distal ends through functional loading and modeling, but any such change will be small relative to the total length of the bone. The main impact on length measures will be mostly genetic and also nutritional. Therefore, discriminant functions based on length measurements will be least influenced by activity-related variation and should be favored for sex determination. The study samples consisted of 123 White females and 136 males from the Terry collection. 3 figures, 9 tables, and 20 references