Burnout has been a major topic in occupational health psychology for the past three decades, and work engagement, presumed to be burnout's opposite, recently gained increasing interest. The two main research questions of this thesis were: (1) To what extent can burnout and work engagement be described in terms of personality dimensions?; and (2) Are burnout and work engagement related to the (stress) physiological state of the body? Burnout was shown to be primarily characterized by high neuroticism, whereas low neuroticism in combination with high extraversion characterized work engagement. With regard to temperament, mobility (the capability to adapt quickly to changes in the environment) characterized engaged persons. It was concluded that burnout and work engagement are associated with personality traits. Two physiological stress systems were examined, that is, the Hypothalamic Pituitary Adrenal axis (HPA-axis), and the cardiovascular system. The HPA-axis is the central mechanism in the long-term adaptation of an individual to his or her environment, and its functioning is measured by cortisol and DHEAS. The cardiac autonomic system consists of two different branches, the sympathetic system and the parasympathetic (vagal) system. The sympathetic system is involved in activity and arousal, whereas the parasympathetic system has a prominent role in recovery and restoration. The burned-out and engaged group neither differed from each other, nor from a control group, with respect to morning cortisol levels, the cortisol awakening response (CAR), DHEAS levels, and the cortisol / DHEAS ratio. The engaged group only showed a slightly stronger cortisol suppression than the burned-out and control group in response to dexamethasone, indicating a higher feedback sensitivity of their HPA-axis. The burned-out and engaged group did not differ either from each other or from a normal control group, with regard to cardiac autonomic (sympathetic and parasympathetic) functioning, as ambulatory measured in their daily life. In addition to the investigation of two specific (stress) physiological systems, the possible impact of stress on different bodily systems simultaneously was also examined, using a composite measure called the allostatic load index. The allostatic load index includes parameters representing different physiological systems (e.g., metabolic and immune system). Burnout was not associated with a higher score on allostatic load as compared to healthy controls, and it was concluded that allostatic load is not a mediator between burnout and impaired physical health (e.g., cardiovascular disease). In short, there is no diagnostic value for peripheral measurements in burnout or work engagement, and they are not useful to predict the future physical health status of individuals. The challenge for future researchers interested in the relation between burnout, work engagement and psychophysiology (or even physical health) is to focus on central mechanisms (e.g., dopaminergic, serotonergic and noradrenergic systems), or on brain processes covered by measures in the field of affective neuroscience (e.g., EEG, fMRI) Keywords: Work Engagement, Temperament, Personality, Neuroticism, HPA-axis, Extraversion, Cortisol, Cardiovascular activity, Burnout, Allostatic load