BACKGROUND Breast cancer has surpassed all other cancers in women becoming the leading cause for mortality. 100 breast cancer cases received in our department of pathology during the period 2016-2017 were evaluated for HER2/neu status and immunohistochemistry correlation with gene amplification by FISH assay. MATERIALS AND METHODS Mastectomy samples received were fixed followed by grossing including all parameters like laterality, size, margin status and adequate lymph node sampling. The tissue sections were stained with H&E for assessing the tumour type, grade, surgical margin clearance study. Lymph node involvement, oestrogen receptor and progesterone receptors Her2/neu was done with immunohistochemistry in the tumour blocks. Subsequently tissue blocks were also subjected to FISH evaluation for Her2/neu. RESULTS The tumour laterality, tumour categorization, staging, and grading were analysed. Comparison of immunohistochemical Her2 results with FISH was done. CONCLUSION Immunohistochemical analysis of Her2/neu with 0 and 1+ Negative. 3+ strong positive had a High concordance with FISH evaluation.