In a 3-year longitudinal study, approximately 300 kindergarten children were selected for testing in the kindergarten and first and second grades to determine predictor variables of future success in reading and arithmetic. Results of the research tended to indicate that age and intelligence test scores were not good predictors of first and second grade reading achievement. It was concluded that the most significant predictors found were as follows: (1) the numbers subtest of the Metropolitan Readiness Test, (2) the Digit Span of the Wechsler Intelligence Scale for Children, (3) the Visual 3 and Complete-A-Man of the Gesell Development Test, (4) titles from the Minnesota Nonverbal Test of Creativity, (5) sex (for first grade reading success), (6) socioeconomic status (for second grade reading and arithmetic achievement), (7) education of the mother, (8) kindergarten teacher's prediction of the subject's reading ability, (9) kindergarten teacher's rating of the pupil's socioemotional growth, and (10) sociometric evaluation of "number of times child is seen in a positive role." Tabulated data and a bibliography with 79 references are appended. (JS)