THE PREDICTIVE ABILITY OF TWO INTELLIGENCE TESTS ON A CROSS-CULTURAL SAMPLE WAS STUDIED. THE STANDARD PROGRESSIVE MATRICES AND THE D. 48 TEST WERE ADMINISTERED TO 1,579 GIRLS IN GRADES 9 THROUGH 12. OTHER TEST SCORES WERE OBTAINED FROM STUDENT RECORDS. THE CROSS-CULTURAL GROUPS CONSISTED OF (1) INDO-EUROPEAN, (2) SPANISH-AMERICAN, (3) NEGRO, AND (4) CHINESE. MEASURES WERE MADE OF ACHIEVEMENT, SOCIOECONOMIC LEVEL, INTELLIGENCE, AND ABILITY. CORRELATIONS AND COMPARATIVE PROCEDURES WERE EMPLOYED IN ANALYSES. SCORES ON BOTH TESTS EMPHASIZED MATHEMATICS APTITUDE AND ACHIEVEMENT. NEITHER OF THE TESTS VALIDLY PREDICTED PERFORMANCE LEVELS, NOR DID THEY DIFFERENTIATE AMONG THE ETHNIC GROUPS. FUTURE RESEARCH WAS SUGGESTED TO SHOW HOW INSTRUMENTS MAY DIFFERENTIATE WITHIN ETHNIC GROUPS AS SOCIOECONOMIC RANK CHANGES. (RS)