In this study, a total of 250 eggs were collected randomly from 50 retail stores in Mashhad city, over a period of three months in summer of 2008. Five samples from each store were collected in sterile plastic bags, and transferred to the laboratory. In order to isolate Salmonella spp., conventional culture method: including pre- enrichment, enrichment, selective plating and differential plating were performed. To confirm the identification of isolated colonies as Salmonella spp. and determining serovars as Typhimurium and Enteritidis serovars, a multiplex PCR (m-PCR) assay, using three pairs of primers were employed. S141 and S139 for InvA gene, specific for the genus of Salmonella, Fli15 and Tym for FliC gene, specific for Typhimurium serovar and Prot6e-5 and Prot6e-6 for Prot6E gene, specific for Enteritidis serovar. Four out of 250 samples (1.6 %) from egg shells were determined as contaminated with Salmonella spp. In m-PCR assay, isolated colonies were confirmed as Salmonella, and their serovar determined as Typhimurium. Salmonella spp. was not isolated from the eggs contents. Practical Applications: It seems that S. Typhimurium is the most prevalent serotype of egg contaminant in the Mashhad area of Iran and m-PCR could be a reliable alternative for conventional culture methods.

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