Salmonella typhimurium phage type 49 which had been isolated from a broiler flock was used at low passage to infect day old specific pathogen free (SPF) chicks. 100% morbidity was observed in chicks directly inoculated with a dose of 0.2 x 10e3 CFU to 2 x 10e3 CFU of this organism or those that were in contact with infected birds. Various degrees of mortality were also observed in different groups of infected chicks. The colonised chicks were carriers of the organism until at least 6 months.