Undergraduate dissertation students’ cognitive appraisal, coping styles and perceived stress were examined at three time points during their undergraduate dissertation projects (UDP), observing whether cognitive appraisal and coping styles predicted perceived stress and their temporal changes. Sixty-four dissertation students completed the Perceived Stress Scale, an adapted Cognitive Appraisal of Health Scale, the Brief COPE and explorative open-ended questions. Linear Regression models for each time-point showed coping styles and cognitive appraisal predicted perceived stress, but single coping styles and primary appraisal harm/loss predicted stress levels inconsistently over time. Analyses indicated significant effects of time-point on primary appraisals benign/irrelevance, harm/loss and challenge but none for secondary appraisal, coping styles or perceived stress. Content Analysis showed perceived stressors and coping styles to be a function of the UDP’s stages and their tasks and challenges. Implications and recommendations for students and supervisors are discussed.