Research Findings: The present study employed a time lag design to assess temporal relationships between motivation, academic achievement, and cognitive development. Eighty-one children from 2 preschool programs were measured twice, with an 11-week time lag, on 2 measures of motivation (marble drop task, bean bag toss task), 2 measures of cognitive development (seriation task, oddity principle task), and 2 measures of academic achievement from the Woodcock-Johnson III (Letter-Word Identification Scale, Applied Problems Scale). There were significant correlations between all of these variables. One clear-cut temporal relationship was found: Prior motivation predicted later academic achievement, but not vice versa. There was also some evidence of temporal relations between motivation and cognitive development, and between cognitive development and academic achievement, but the evidence for these relations was not as conclusive. Practice or Policy: It appears that at the preschool level, maintaining children's motivation is paramount. Curricula should be shaped with that primary goal as a high priority, as it appears that it will be followed by academic progress. (Contains 7 tables and 6 figures.)