Ninety random samples of fresh beef were collected from the cattle carcasses slaughtered at 3 different abattoirs in Menoufia governorate namely A, B and C (30 of each), represented by neck region (chuck) during summer and winter seasons in 2018 (45 samples of each season). The obtained results of serotyping of E. coli revealed that EHEC O26: H11 were the more prevalent than other serogroups 6.67%, 6.67% &13.33% and 6.67%, 13.33% & 6.67% .T The results of the total incidence were 46.67% , 40% & 26.67% and 26.67%, 26.67% & 20 for A, B&C abattoirs during the summer and the winter seasons , respectively. Serotyping of salmonella revealed S.Typhimurium was more prevalent during the summer 13.33%for each abattoir, the total isolation rate 33.33%, 26.67% & 20% for A, B and C abattoirs, respectively. The more prevalent serogoup during the winter was S. Enteritidis 13.33%, 6.67% and 6.67%,while the total isolation rate was 26.67% , 20% and 6.67% for A, B &C abattoirs, respectively .The contamination rate increased in abattoir A than B than C and the prevalence was increased during summer than in winter