BACKGROUND: Intensive care units are characterized by heavy workloads, increasing work complexity and ethical concerns related to life-and-death decisions. In the present study, it is assumed that there is a relationship between moral stress, support and competence for nurses in intensive care units. AIM: To analyse and describe the theoretical relationship between moral stress and support on the one hand and competence on the other, in the context of intensive care. METHOD: A form of qualitative secondary analysis based on the findings from three original studies. In the analytic process a theory on professional competence was used. FINDINGS: The findings suggest that imbalance due to moral stress between different competences hinders the development of collectively shared caring competence. CONCLUSIONS: Moral stress cannot be totally eliminated in the intensive care unit. But moral stress is not only a problem. It can also become a driving force to stimulate competence.