The human epidermal growth factor receptor-2 (HER2), which is expressed in large amount in 20%-30% of breast cancer patients, is associated with disease recurrences, shortened disease survival, and bad prognosis. The aim of this study is to evaluate the expression of (Her2/neu) receptor as a diagnostic and prognostic marker in Invasive Ductal Breast cancer in Sudanese female patients. The study was performed on 35 archival paraffin blocks previously diagnosed as invasive ductal breast cancer (IDC), then a second diagnosis was done using IHC staining (Her2/neu). The obtained information is arranged in a standard master sheet, then analyzed using a statistical package for social science (SPSS) version 20 computer program. The age 30-45years was the most frequent age group 48.6% (17/35), followed by 46-60 years 40% (14/35). The majority of samples were grade III 74.3% (26/35) and the samples of grade II were 25.7% (9/35). the majority of TMA results were positive for Her2/neu receptor 65.7% (23/35) and the negative results were 34.3% (12/35) the majority of TMA score were (+) 31.4% (11/35), followed by (++) 17.2% (6/35), then (+++) 11.4% (4/35), then (++++) 5.7% (2/35), and the negative result were, 34.3% (12/35). There was a significant relation between H&E diagnosis with TMA result for Her2/ neu diagnosis that the P-value (0.0002). There was an insignificance relation between H&E diagnosis of grades with TMA results for Her2/ neu diagnosis that the P-value (0.08). In conclusion, HER2 is over-expressed in 65.7% of the patient while internationally it is over-expressed in 15-30%. This provides valuable prognostic and predictive implications in order to choose the suitable treatment for the patients.