Since 1989, an undergraduate course addressing issues concerning biotechnology in agriculture has been taught annually. To determine the extent to which students were engaged in classroom instruction and assimilated knowledge from the course, students were asked to complete an 'Attitudes About Biotechnology' questionnaire. Students were queried about their knowledge of biotechnology, perceptions of risks associated with biotechnology, and ethics and attitudes toward the use of biotechnology in agriculture. Responses to the survey questions were evaluated both pre-and postcourse. Data were collected from 13 classes over a 10-yr period. Inspection of the precourse grade point average and the course grades for these students revealed no trends up or down over the period of this study. Similarly, inspection of the data revealed no effect from problem-based learning, student-facilitated group work, or technology on student attainment of knowledge, perception of risk, or ethical views. For each of the five knowledge questions, the average score increased as a result of taking the course. On two of the knowledge questions, the average score increase for females from pre- to postcourse was greater than for males. Based on our measurements using the postcourse questionnaire, the correlation between perceived and actual knowledge was not significantly different from zero. In two of the four risk questions, there was no change in average score as a result of the course; however, student perception of risk associated with genetic engineering of plants increased. Although average scores for student perception of risk due to the perceived impact of genetically engineered products on people or the environment decreased from pre- to postcourse assessment, the average score was higher (P < 0.01) for females than for males. Males were more accepting of genetic manipulation of cells in a laboratory than were females both pre- and postcourse. Although student knowledge of biotechnology was increased and the perceived risk due to biotechnology was altered, there was no evidence that students altered their ethical position on biotechnology as a result of this course.