A total of 543 cases of listerIosis were ascertained by the Public Health Laboratory Service Communicable Disease Surveillance Centre (PHLS CDSC) in residents of England and Wales with onset of illness between 1st January 1995 and 31st December 1999. Of 452 non-pregnancy associated cases, 326 (72%) had major medical conditions, 140 (31%) had received immuno-suppressive therapy and 97 (21%) were aged 60 years or over. Serovar 4b predominated in both pregnancy and non-pregnancy associated cases. Of ninety-one pregnancy associated cases, five had underlying medical conditions. Foetal death or early neonatal death was reported in 24 (26%) of the cases giving a mean perinatal mortality rate of 7.5 per million conceptions per year. Two episodes of neonatal cross infection occurred. Two non-pregnancy associated cases in 1999 were linked by a common food; all other cases were unlinked. No trend was observed from 1995 to 1999.