Demolition or renovation works adjacent to hospitals pose risks of fungal airborne infections. During November 2005 and March 2006 an old building with three floors was demolished on the area of University Hospital of Essen. To prevent dust exposure the building was sealed up by impermeable plastic foil and mechanical disruption of structures was accomplished using excavators. Dust emission was minimised by water jet. To determine if there were any infectious risks for patients from emissions from the demolition work we monitored particle and fungal concentration of the air before and during demolition. Air sampling was performed at seven positions around the building and weather conditions were monitored at the same time. Concentrations of ultrafine particles, particles ≥0.3, ≥0.5 and ≥1μm were significantly higher during demolition than before, but only by small factors (ultrafine particles 1.6-fold, particles ≥0.3μm 1.6-fold, particles ≥0.5μm 2.9-fold and particles ≥1μm 3.3-fold). Concentrations of moulds which could be cultured at 37°C did not differ between the two periods (median before demolition: 66cfu/m³; median during demolition: 80cfu/m³). Concentrations of moulds which grew at 22°C correlated significantly with temperature and humidity and were significantly higher before (median: 510cfu/m³) than during the demolition period (median: 210cfu/m³). We conclude that the fungal infection risks for patients during demolition work in hospital areas is not increased by demolition if protective measures are in place.