Introduction: Caregivers' emotions can affect the quality of life of patients with epilepsy. The purpose of this study was to investigate the mediating role of dimensions of spiritual intelligence in the relationship between mindfulness and expressed emotion in the caregivers of epileptic patients. Materials and Methods: This was a descriptive cross-sectional study. The study sample consisted of 90 epileptic patients and their caregivers that were selected by convenience sampling method and responded to the expressed emotion, Kentucky Mindfulness Skills, and Spiritual Intelligence questionnaires. The hypothesis of the research was investigated by hierarchical regression analysis using the proposed steps of Baron and Kenny. Results: The hierarchical multiple regression analysis showed that in the first step, mindfulness (beta=-0.39) can predict expressed emotion. In the second step, mindfulness (beta=-0.28) and only the ability to deal with problems dimension of spiritual intelligence (beta=-0.27) predict expressed emotion. Due to the decrease of the beta value of mindfulness in the second stage compared to the first stage, the partial mediating role of the ability to deal with problems in the relationship between mindfulness and the expressed emotion is confirmed. Conclusion: Mindfulness is associated with the expressed emotion of caregivers of patients with epilepsy, and the ability to deal with problems as one of the dimensions of spiritual intelligence plays a mediating role. Therefore, it is suggested to pay more attention to psychological training in promoting the mindfulness and spiritual intelligence of caregivers of epileptic patients.s