TThe present study was designed to genotype Staphylococcus aureus isolated from mastitis cows. One hundred cow's milk samples were gathered (50 clinical and 50 subclinical mastitis milk samples) from various dairy farms in various regions of Egypt's El-Gharbia governorate. S. aureus was isolated and identified from the samples using bacteriological and molecular examination. Genotyping was subsequently carried out using the Enterobacterial Repetitive Intergenic Consensus-PCR (ERIC-PCR). According to our findings, the prevalence of S. aureus was 30% and 12% from clinical and subclinical mastitis milk samples respectively. Discriminatory index of ERIC-PCR was 0.977. The dendrogram analysis of the isolates showed one cluster, two sub clusters, and four separate isolates. The same cluster contained some strains obtained from various regions, while some strains collected from the same region and also the same farm were located in different clusters. This suggested the possibility of infection transmission between these regions, requiring increased control measures, management practices and decreasing the transmission of the diseased animals between these regions to prevent the transmission of different genotypes between them and increase the cure rate of the disease. In conclusion, ERIC-PCR was a reliable genotyping approach for S. aureus isolates with high genetic diversity and a high discriminating index. ERIC-PCR is a useful molecular epidemiology approach for S. aureus isolates as there was a genetic similarity between some strains gathered from several regions at the El-Gharbia governorate in Egypt.