The purpose of this study was to investigate the level of psychological stress as well as the perceived sources of stress among undergraduate dental students at the University of Jordan. The top perceived stressors were compared with those of a previous study that examined the perceived sources of stress among undergraduate dental students at the University of Jordan in the year 2000. Psychological stress was assessed using the General Health Questionnaire (GHQ-12). Perceived sources of stress were evaluated using the Dental Environment Stress questionnaire. In the study, 520 students completed the questionnaires, for a response rate of 74 percent. These students showed a high level of psychological stress, with 70 percent at the cutoff point of a score of more than 3 for the GHQ-12. Women had a higher level of stress than men: 73 percent scored more than 3 on the GHQ-12 vs. 63 percent for men, which was statistically significant at p=0.05. The top perceived sources of stress from the year 2000 were mostly unaltered in our study, despite a substantial increase in the number of students as well as changes in the curriculum. Further research is needed into methods to minimize stress on dental students.