This report describes an assessment of substance abuse among Portland (Oregon) Public School students in grades 7 and 10, determining the relationship between early and later substance use for planning and development of alcohol and drug education, prevention, and intervention. The survey was administered in 17 middle schools, 10 high schools, and 2 alternative schools to a total of 5,661 students. Alcohol is the students' drug of choice by far, and alcohol and other drug use increases systematically by grade. More than 50 percent of seventh graders and four of five tenth graders reported alcohol use in their lifetime. One-third of tenth graders had tried marijuana, and many had experimented with inhalants (18 percent), amphetamines (12 percent), with lysergic acid diethylamine--LSD (11 percent). There are gender differences and geocultural group differences in use patterns. For example, more adolescent females than males use tobacco. American Indians reported higher use of several substances than other groups. Most high school students report getting alcohol from friends, while elementary school students report getting alcohol from their parents. School is the most important source of information on the dangers of alcohol and drugs. Few students reported drug use during school activities; students reported using alcohol and drugs at home and at parties. Survey findings on student substance use are presented in eight graphs and two tables. Four appendices provide the survey instrument and survey results by grade and gender. Six references are listed. (SLD)