The paper presents details of sessions taken place for a mourning female patient case study with cognitive behavior theoretical basis. The main objective is to present the clinical intervention: the list of cognitive distortions linked to the mourning process, the challenge of dysfunctional thinking, inventory scores and the coping card built along with the patient. It describes the step by step in the care of a mourning patient and proves the effectiveness of the chosen protocol for this purpose. The results show that after the application of the focused and structured protocol there was significant improvement in the patient’s interpretations regarding her son’s death. The evidences towards such a conclusion are the greater capacity of the interpretation’s understanding and reassessing, the emission of functionally more effective behavior in producing more reinforcing consequences for the patient in face of missing her son, and more positive emotions.