A master's thesis at the faculty of The College of Science at the University of Basraha (Prevalence of Epstein - Barr virus and Cytomegalovirus among Patients with Cancer), and showed the researcher's thesis (Aseel Abdulhasan Kareem) Breast cancer is the most common type of cancer in Iraq. Accumulating evidence from the past 10 years indicates that cytomegalovirus (HCMV) and Epstein-Barr virus (EBV) are associated with various types of human cancers, including breast cancer. Understanding this association may be critical for understanding breast cancer. Thesis aims to detect the prevalence of EBV, HCMV, and the EBV genotype in formalin-fixed paraffin-embedded blocks (FFPE) women with breast cancer and determine whether EBV and HCMV are associated with breast cancer using a molecular technique (PCR) and Histopathological study of paraffin-embedded tissue blocks and the study concluded that the presence of these viruses in most tissues of patients with breast cancer, as well as benign tumors. Grade 3 invasive ductal carcinoma was the most prevalent compared to invasive lobular carcinoma in terms of determining the presence of both viruses. The first type is the predominant type of Epstein-Barr virus in these samples. The study recommended Additional study with larger scale specimens may be give more information about the prevalence of breast cancer associated with EBV and HCMV in Basrah province, studying the role of these two viruses with other cancerous diseases like prostate cancer , comprehensive study of protein expression from EBV, and HCMV ‎that are responsible for cancer.