An agar medium for the isolation of Salmonella spp. is described. The medium, lysine-mannitol-glycerol agar, has features of both xylose-lysine-deoxycholate agar and mannitol-lysine-crystal violet-brilliant green agar, but glycerol is added for the differentiation of Salmonella and Citrobacter spp. The medium facilitates the detection of strains having atypical fermentation patterns, such as the lactose- or sucrose-positive salmonellae. The medium also detects Salmonella typhi after enrichment.