The tumour suppressor gene p53 and the proto-oncogene Bcl-2 encode respectively, for a nuclear phosphoprotein and for a mitochondrial membrane protein involved in multiple cellular functions. Both proteins are linked to programmed cell death pathways and provide prognostic information on breast carcinoma. Our aim is to study the expression of p53 and Bcl-2 oncoproteins in breast carcinoma and correlate with patients’ age, tumour size, disease stage and histological grade. Fifty nine cases of breast carcinomas from Universiti Kebangsaan Malaysia Medical Centre (UKMMC) were studied with the immunohistochemical method. Our results showed 45.8% (27 of 59) and 40.7% (24 of 59) of the breast carcinomas were immunopositive for p53 and Bcl-2 respectively. There was significant correlation between Bcl-2 expression with early tumour stage (p=0.01). No significant relationship was seen with other variables. Results also showed an inverse relationship between p53 and Bcl-2 expression (p=0.001). These findings indicate a down regulation of Bcl-2 by p53 in breast carcinogenesis.