This study investigated the relationship between number of hours worked, or work intensity, and substance use in a sample of adolescent employees of a supermarket chain. Employees working half-time or more per week (high-intensity hours) were over three times as likely to smoke compared to those working an average of 10 hours or less per week (low-intensity hours). Males working a high intensity number of hours were more than twice as likely to drink compared to males working at low intensity. Utilizing participants drawn from a uniform employment setting, the research findings add to the growing body of evidence linking work intensity with adolescent substance use.