Stress coping strategiesBackground: Cancer is one of the most important diseases of the present century worldwide.Patients and their spouses can find more difficulty accepting the diagnosis of cancer than its phases of treatment. Both the physical health and mental health of the patient and spouse are important in the process of recovery from cancer and its treatment. Objective: The aim of this study was to determine the relationship between coping strategies for stress and self-efficacy in patients with cancer and that of their spouses. Methods: In this descriptive-analytical cross-sectional study, 91 patients and their 91 spouses completed the Endler and Parker Coping Inventory, the Sherer General Self-Efficacy Scale, and a demographic information questionnaire. Results: The problem-oriented coping style was used more than the other strategies by patients with cancer and their spouses. The least used coping style by patients and their spouses was the avoidance style. The self-efficacy of patients and their spouses was above average. Self-efficacy was directly and moderately correlated with problem-oriented coping style (P < .001) and inversely and moderately correlated with emotion-oriented coping style (P < .001). Conclusions: Adoption of strategies like training and consulting may enhance the problem-focused coping style and reduce emotion-focused coping style and therefore lead to increased self-efficacy in patients and their spouses.Implications for Practice: Healthcare providers', especially nurses', knowledge and sensitivity about the coping strategies of patients with cancer and their spouses may help providers select more effective interventions for improving patients' and their spouses' effective coping styles and self-efficacy.