This research paper reviews the subject of psychological testing in personnel selection. The history of employment testing is traced from its beginnings in World War I to current day testing practices. Tests are described in a five category classification: intelligence, aptitude, performance, interest and personality tests. Next the various psychometric properties of tests are discussed: standardization of a test, objectivity, the different kinds of norms and reliability, and the different types of validity. The latter two topics are dealt with in some detail. The recent findings of validity generalization and its implications are considered. A section on decision theory and utility follows a discussion of classical test validation procedures. The advantages of tests are discussed in terms of test characteristics, recent research on productivity increases with valid testing programs, and alternative predictors. The following section covers the limitations of tests in three areas: the misuse of tests; test bias; and ethical concerns regarding privacy. In the concluding comments, it is noted that there are no better predictors than tests, but that tests are only one part of the personnel process. Also, the recent research findings reviewed here have yet to influence the real world of employment testing.