This study describes the lifetime prevalence and future intentions related to trying cigarettes, chewing tobacco, alcohol, marijuana, and inhalants of students in the 1st through 7th grade. This article also describes the identification of these substances by children in the 1st through 3rd grade. Participants were 1,075 1st through 5th graders within a school district in western Oregon who were followed for 3 years. Across most substances, prevalence and intentions increased with grade, with a moderate increase between 3rd and 4th grade and a larger increase between 5th and 6th grade. Boys were more likely than girls to identify alcohol and cigarettes and were more likely than girls to report trying chewing tobacco. In addition, 3rd-grade boys were more likely to identify marijuana and, in the early grades, alcohol. Boys were also more likely than girls to intend to use tobacco and drink alcohol when older. For alcohol and cigarettes, intention was related to subsequent trying of the substance, suggesting that intention may be an early warning sign of subsequent substance use.