In February 1994, three cases of conjunctivitis with Serratia marcescens occurred in infants in the newborn nursery. An epidemiological investigation was conducted including environmental sampling. S marcescens was isolated from the bottle of triclosan 0.5% antiseptic soap that was in use in the nursery and from an unopened bottle on the pharmacy shelf. The manufacturer confirmed that this contaminant was dislodged from the air purification system during a filter change while the packaging was being completed in an adjoining room. The product was withdrawn from use in the nursery and replaced by individual bar soap. No further cases of infection with S marcescens have been identified following the withdrawal of the triclosan 0.5% soap.