Background: P53 is a tomour suppressor gene that plays a critical role in preventing human cancer formation. In response to a variety of of stress signals p53 becomes activated and induces cell cycle arrest and/or apoptosis. We Aimed to: 1. study the immunohistochemical profileof p53 in breast carcinoma (BC). 2. Assess its prognostic value in relation to clinico-pathological prognostic factors of BC. Subjects and Methods: This study included 45 specimens of BC. Patient's age, tumour size and local aggressive changes, history of recurrence and/or presence of distant metastases were obtained. H&E stained sections were evaluated. P53 immunostaining was done to detect its expression using the avidin-biotin peroxidase method. Results: P53 was weakly expressed in 11% of benign breast disease, negative in all cases of low grade DCIS, positive in 2/3 of intermediate grade DCIS, and in all cases of high grade DCIS. All grade 1 invasice BC (IBC) were -ve for p53, 50% of grade II and 91% of grade III IBC were +ve for p53. P53 expression increased significantly with increased tumour grade of IBC (p<0.006), lymphovascular invasion (p<0.003) and lymphocytic infilteration (p<0.004). No significant correlation between p53 expression and lymph nodal status. Conclusion: P53 is an indicator for poor prognosis in BC being positively correlated to tumor grade, presence of lymphovascular invasion. P53 may modulate the immune response in BC being positively correlated with prominent lymphocytic infilteration.