SummaryIn an investigation of 1825 strains of a wide variety of Salmonella serotypes and Kauffmann‐White groups, between 5 and 10% were found to produce colicin‐like antibiotics, and at least 40% produced phage; the majority were sensitive to salmonellin, and about 40% of those tested were sensitive to at least one colicin. It is suggested that some combination of these characters might be useful for exact strain identification.