Objectives: Evaluating the effectiveness of a group psycho-educational program on family caregivers of inpatients with mental disorders in Noor Hospital in the city of Isfahan. Method: The present study was a single blind randomized clinical trial, and assessed the effective-ness of a group psycho-educational program on 100 family caregivers of psychiatric inpatients over a three month period, in Noor Hospital affiliated to Center for Behavioral Science Research of Isfahan University of Medical Sciences. Caregivers’ burden was assessed using Zarit Burden Interview ZBI. Results: The results showed that the mean score of burden in family care givers of patients with schizophrenia and mood disorders significantly decreased (p=0.001) in comparison with the control group. Conclusion: The group intervention program for reducing caregivers’ burden in family caregivers of patients was effective, and this could potentially improve the quality of life of both patients and caregivers.