This report presents results of a study of alcohol and other drug use by Wisconsin students which was conducted in the spring of 1991. A total of 5,834 students were surveyed. Students were from grades 6, 8, 10, and 12, as well as from various community sizes and racial/ethnic groups. In addition to reporting results of the 1991 survey this report compares baseline data from a similar 1989 survey with data from the 1991 survey. Results in these categories are presented: (1) social context; (2) alcohol use; (3) cigarette and smokeless tobacco use; (4) marijuana, cocaine/crack, and amphetamine use; (5) other drug use; (6) categories of problem use; (7) percentage of students at risk; (8) comparisons to national norms; (9) summary of changes on selected measures of alcohol and other drug use, 1989 and 1991; (10) community size differences; (11) school and community resources; and (12) opportunities. A recent national study which identified characteristics of youth and the environments that appear to discourage alcohol and other drug use and other forms of at-risk behavior is summarized. Results are illustrated with tables and graphs. Appendices list 1988-1989 sample characteristics and discuss margin of error. (ABL)