-Background and Objectives: Work on the oncology department has proved to be very stressful, so the medical staff indirectly copes with it by trying to escape it through the ego-defense mechanisms. On the other hand, working on the physical medicine department does not seem to be so stressful. The objective of this study was to determine the main ego-defense mechanisms at oncology and physical medicine department and to explain the differences between their frequencies. The other part was to obtain data about socio-demographic status and working environment of the participants.Methods: General structural interview for collecting data on socio-demographic status and working environment and Life Style Questionnaire and Defense Mechanisms for obtaining data about ego-defense mechanisms were carried out among a random sample of 40 medical staff members at each department. Results: A significantly higher level (p ≤ .05) of the following ego-defense mechanisms has been found at the oncology department: regression, intellectualization, projection and dislocation. Also, statistically significant difference (p ≤ .05), showing higher score on oncology department is observed in following variables: death of patients, facing the patient or his family with possible death, being overloaded with number of patients, facing pain, suffering and handicap, insufficiency of medications, insufficient positive feedback from the patients and bad interpersonal relations at work as well as lack of support from the colleagues.Conclusions: Extreme exposure to stressful events at the oncology department favours development of inadequate defensive mechanisms among the medical staff, which may enhance the risk of burnout.