WHEN MEDICAL EXAMINERS OR CRIME LABORATORY PERSONNEL MUST DETERMINE THE SEX AND RACE OF AN UNIDENTIFIED SKELETON, THEIR BEST REFERENCE SOURCE IS THE PHYSICAL ANTHROPOLOGIST WHO, IN THE COURSE OF A CAREER, MAY HAVE EXAMINED HUNDREDS OF SKELETONS. IN 1962, E. GILES AND O. ELLIOT, TWO PHYSICAL ANTHROPOLOGISTS, PUBLISHED A SET OF DISCRIMINANT FUNCTIONS (DF) FOR THE DIAGNOSIS OF SEX AND RACE. FIVE MEASUREMENTS AND APPROPRIATE WEIGHTING COEFFICIENTS ARE USED TO DIAGNOSE SEX; CRANIAL LENGTH, BASION-NASION LENGTH, BIZYGOMATIC BREADTH, BASION-PROSTHION LENGTH, AND PROSTHION-NASION HEIGHT. IF THE DF SCORE IS LESS THAN 891.12, IT IS CLASSIFIED AS FEMALE; IF GREATER, AS MALE. TWO DF (SEX AND RACE), EACH USING ALL EIGHT CRANIAL MEASUREMENTS, DETERMINE THE RACE. THE MEASUREMENTS ARE PLOTTED ON A GRAPH AND THE RACE IS DETERMINED BY THE ZONE WITHIN WHICH THE POINT PLOTTED FOR THE UNKNOWN SPECIMEN FALLS. IN A SERIES OF 52 FORENSIC CASES, SEX WAS CORRECTLY DETERMINED IN 46, OR 88 PERCENT; THE METHOD WORKED EQUALLY WELL FOR MALES AND FEMALES. IN THE GILES AND ELLIOT SAMPLE OF 1022 CRANIA, SEX WAS CORRECTLY DIAGNOSED IN 82.9 PERCENT. THE DF CORRECTLY IDENTIFIED 22 OF THE 27 KNOWN-WHITE CRANIA AND 7 OF THE 8 KNOWN-BLACK, BUT ONLY 1 OF THE 7 KNOWN-INDIAN CRANIA. THE MEASUREMENTS WERE VALIDATED ON AN ANCIENT POPULATION AND EVIDENTLY DO NOT REFLECT CONTEMPORARY AMERICAN INDIANS. FACTORS WHICH AFFECT DIAGNOSIS ARE DISCUSSED. THE ARTICLE IS ILLUSTRATED AND CONTAINS REFERENCES. (GLR)