Care burden is substantial among caregivers of patients with both bipolar disorder and schizophrenia but there is no statistically significant correlation between two groups when compared. Most important variables which increased care giving burden of patients’ relatives found in our study were lower level of education of patients’ relatives, severity of disease, proximity of caregivers (spouse>parents), presence of psychiatric disorder in another member of the family. It is important to determine factors affecting care burden in relatives of patients due to their value to predict relapses.