In August 1950 nine aptitude and achievement tests constructed by the Educational Testing Service under an Office of Naval Research contract were given to the members of the incoming class at the U. S. Naval Post- graduate School. Two tests provided by the Research Division of the Bureau of Naval Personnel were also administered. Scores on these eleven tests have now been studied in relation to the quality-point ratios earned by officers in this class for their first two terms at the Postgraduate School. Bar charts are presented showing for each of four score intervals on each test what per cent of students achieved quality-point ratios of 2.0 or higher. In addition, product-moment coefficients of correlation between scores on each test and the criterion of quality-point ratios have been obtained. The most effective of the tests for predicting this criterion were the Mathematics Aptitude Test, the Advanced Mathematics Test, the Physical Science and Engineering Test, the Interpretation of Data Test, and the two BuPers tests: General Mathematics NAVPERS and General Physics NAVPERS. Results of the 1950 experimental tests were found to be highly consistent with those obtained from the 1948 and 1949 tests.