Breast cancer and its subsequent treatment are a great source of anxiety and depression in patients. However, it remains unclear whether this decrease in mental and physical health is temporary or if long-term effects would appear once the patient is well out of these stressful times. Methods: a total of 204 women were included in the present analysis. Participants were recruited at tertiary care hospital (EL- Maadi oncology hospital). Results: the mean age of the included patients was 56.76 ±17.5 years old; almost one-third of them aged between 51-60 years old. In our cohort, the mean BDI-II was 15.4 ±29.4. A total of 48 patients (22.5%) had depression. Of them, 13 patients had mild depression (6.4%), 14 patients had moderate depression (6.9%), 9 patients had severe depression (4.4%), and 10 patients had extreme depression (4.9%). there were statistically significant associations between presence of depression and overall WHOQOL-BREF score (p < 0.001), physical domains (p <0.001), psychological health (p <0.001), social relation (p <0.001), and environment score (p <0.001); depressed patients exhibited lower scores in all of these domains than non-depressed patients. Conclusion: breast cancer is often accompanied by severe psychological distress, which is associated with a significant prevalence of anxiety and depression disorders in the course of the disease. Depression may reduce the efficacy of chemotherapy, and therefore the survival chances of cancer patients. This study provided evidence that depressive symptoms in patients with breast cancer undergoing treatments  detrimentally affected various aspects of the QOL in a real- world setting.