The Texas School Survey of Substance Abuse, which has been administered twice, and which covered grades seven through twelve, was expanded for the 1990 survey to encompass grades four to six. The students were surveyed on their use of tobacco, alcohol, inhalants, and marijuana. The most widely used substances were alcohol and tobacco, with inhalants third in prevalence and marijuana fourth. Substance use is lower in grades four through six than in secondary grades, with younger students about one-half as likely to report experimentation with alcohol and inhalants and almost one-third as likely to have used tobacco. Secondary students are about ten times more likely to have used marijuana than elementary grade students. Grade level, ethnicity, urbanicity, gender, academic performance, and family structure are all associated with the use of drugs or alcohol by elementary students. The sixth grade in particular marks a substantial increase in substance use compared to fourth and fifth grades; over one-half of sixth-graders have tried alcohol. Although prevalence in the elementary grades seemed quite low compared to secondary students, many students are first exposed to drugs and alcohol in elementary school. Interestingly, survey results indicate that fourth and fifth graders actually receive more education about substance use than sixth graders, with schools seeming to concentrate on early prevention programs. This may be a questionable strategy since widespread experimentation seems to begin in sixth grade. (CC)