This study examines interrelations among students’ educational engagement, desired and actual school-year employment, substance use, and other problem behaviours. Cross-sectional findings from representative samples of 8th-, 10th-, and 12th-grade students in the United States, totalling over 300,000 respondents surveyed during the years 1992–1998, include the following: Large majorities of adolescents wish to work part-time during the school year, although most in earlier grades are not actually employed. Those who desire to work long hours tend to have low grades and low college aspirations; they are also more likely than average to use cigarettes, alcohol, and marijuana. Students’ preferences for part-time work emerge at younger ages (i.e., earlier grades) than actual work, and the preferences show equal or stronger correlations with educational disengagement and problem behaviours.