Sixty patients of endogenous depression and thirty normal controls were studied to find out the relationship of post dexamethasone plasma Cortisol levels (PDPC) and clinical improvement of endogenous depression inpatients treated with electroconvulsive therapy and imipramine. The PDPC levels in both the group of patients showed significant decrease with clinical improvement (Pre and post treatment PDPC values of ECT group was 20.7 ug/dl and 13.6 ug/dl while it was 17.9 ug/dl and 12.7 ug/dl respectively for the Imipramine group). A significant correlation was also found between PDPC and severity of illness (p< 0.001) in the both groups which indicates that PDPC levels is independent of treatment modality used.