Data from over 1,200 correlations reported in 38 studies concerning validity of aptitude and achievement predictors of success in high school vocational programs are summarized. Predictors investigated were (1) verbal intelligence, (2) nonverbal intelligence and abstract reasoning, (3) arithmetic reasoning, (4) spatial aptitude, (5) mechanical comprehension, (6) perception, (7) manual dexterity, (8) specific purpose aptitude tests, (9) grade point average, and (10) achievement tests. Correlation coefficients were used as the index of relationship between the predictor and criteria. Findings revealed (1) substantial variation in results from study to study, (2) some rather sharp differences in the levels of correlation obtained for the various predictors within a given vocational area, (3) greater predictability of success in some vocational areas than in others, (4) success of girls in vocational areas more highly predictable than that of boys, and (5) low levels of predictive validity for dexterity tests. As a way to meet the need for more useful data, a center for the validation of aptitude tests was proposed and its major functions described. (DM)