Hungarian hospitals have been declared smoke-free since 2005. To date, there is little information on compliance with this law, although the presence of ashtrays and cigarette litter evident inside many hospitals suggests that compliance is less than 100%. The purpose of this study was to document compliance with the smoke-free hospital law in a large public hospital in Budapest, Hungary. The study was conducted between January and April 2009 during the morning shift (8:00–15:00). TSI SidePak AM510 Personal Aerosol Monitor was used to measure the concentration of particulate matter less than 2.5 μm diameter (PM2.5) in the ambient air of 117 locations sampled in …