The purpose of this study was to identify the perceived stress of third-year dental students using a large sample (four classes). The dental environmental stress (DES) questionnaire was administered to 263 (87.7 percent) third-year students from 1984 to 1988. The top six stress items, as perceived by third-year students, included examinations and grades, graduation requirements, inconsistency of professor's feedback, patient tardiness or no show, atmosphere created by clinical faculty, and financial responsibilities. In addition, 15 of the 38 DES questionnaire items were considered moderately stressful or very stressful by at least 34.0 percent of the students.