The purpose of this research was to investigate the relationship between self esteem and depressive mood of psychiatric patients with mood disorders. It was hypothesized that there would be negative relationship between self esteem and depressive mood in psychiatric patients with mood disorders. To test the hypothesis the correlational study design was adopted. Through purposive convenient sampling N=100 individuals diagnosed with major depression, bipolar I disorder most recent episode hypo manic, bipolar I disorder most recent episode manic, and dysthymic disorder based on the criteria of ICD-10 were approached from OPD of a psychiatric hospital of Karachi, Pakistan. Their mean age was 31.37. After the consent of the hospital administration as well as of the patients, their personal information data sheet was filled with the help of their case files and then they were requested to complete Rosenberg Self Esteem Scale and Goldberg Depression Scale. Through SPSS Pearson Product Moment Correlation was applied. It denotes that there is a significant negative correlation between self esteem and depressive mood of psychiatric patients. Hence, it is concluded that when self esteem of individuals with mood disorder is low, then their depressive mood is high; and when their self esteem is high, then their depressive mood is low. This study has positive implications as it would be beneficial for psychiatrists, clinical psychologists and other field practitioners of clinical group in understanding more easily and handling patients with above mentioned diagnosis.