The efficacy of decontamination using Sterilox fog was assessed against meticillin-resistant Staphylococcus aureus (MRSA) and Acinetobacter baumannii. Ceramic tiles were inoculated with the test organisms and, once dried, were subjected to Sterilox fogging using a stationary vaporizing machine sited at a distance of 3m for 10 min and then left for a further hour. In a second experiment using the same organisms, the first 10-min fogging period was followed by a directed fogging period of 30s at a distance of 1m. Organisms were cultured from the tiles, plated on to tryptone soya agar and incubated for 48 h. Initial counts of approximately 10(9) colony-forming units/mL for both organisms were reduced approximately 10(4) fold for MRSA and 10(5.8) fold for A. baumannii when using a single fogging. The second fogging resulted in 10(6.8)-fold reductions for both organisms. Sterilox fog is safe and simple to use, and can reduce levels of nosocomial pathogens by a factor of almost 10(7). It is worthy of clinical evaluation in clinical settings to determine whether it maintains its microbicidal effects against a variety of organisms on different surfaces.