To evaluate an isolation policy for patients colonised with vancomycin-resistant enterococci (VRE), we instituted active surveillance for transmission to uncolonised patients. Surveillance rectal swabs were taken and pulsed-field gel electrophoresis was performed on positive isolates. VRE transmission with an identical genotype occurred in 5 patients, giving a transmission rate of 3.7 per 1000 patient days, or 1 patient per ward each week. The present study provides a baseline for -assessment of VRE transmission and will be useful in evaluation of the effectiveness of infection control interventions.