Salmonellae are considered one of the most important microorganisms that cause diseases in man and animals. The current research aims to obtain complete picture of Salmonella typhimurium. Two hundred four rectal swabs (140 cow calves and 64 lambs) were collected from apparently healthy and diarrhoiec cases in Sharkia Governorate. All rectal swabs were subjected to both bacteriological and serological examination. The total incidence of positive samples was 15 (10.7%) Salmonella typhimurium isolates obtained from 140 cow calves, in addition to 6 (9.37%) isolates from 64 lambs rectal swabs. Six Salmonella typhimurium serotypes were detected by PCR for invA gene, all tested isolates gave characteristic band of invA gene at 521 bp. Moreover, antimicrobial drug sensitivity were carried out.