Objective: Detection of Her2neu amplification is an integral part of breast carcinoma diagnostics to decide therapy. Method: We study 55 cases of breast carcinoma embended paraffin tissues, both CISH and FISH were performed on each case using (SPoT-Light HER2) for CISH and both Her-2 and chromosome 17 probes for FISH (Vysis). Sixty tumor cells were evaluated in each case. The scoring system and interpretation of CISH -INVITROGEN. Results: Concordance between CISH and FISH was found in 94,8 % cases, considering FISH as gold standard, sensitivity of CISH was 97.5 % and specificity 94 %. CISH is more practical alternative due to lower cost, no requirement of fluorescence microscope, use of existing bright-field microscopy and techniques it s similar to IHC, archivable and quantitative results, it s easy to observe both the tissue morphology and the gene amplification evaluation Of the 55 cases analyzed, 53 showed similar results for both methods. Two cases were discordant. In these cases, low-level amplification was suggested by CISH but nonamplification by FISH. Conclusion: our results, suggest that CISH is a useful technique to determine Her-2/neu oncogene status, in breast carcinoma for paraffin embendded tissues, is a highly accurate, reproducible and practical technique, with a high sensitivity.