Background: It is currently believed that most fungal exposure occurs external to the home. Aims: To enumerate the fungal flora of used synthetic and feather pillows and the dust vacuumed from them, in the UK. Methods: 10 pillows aged between 1.5 and >20 years in regular use were collected and quantitatively cultured for fungi. Swatches were taken from nine sections of the pillow and dust was also collected by vacuum from five pillows. Pillow vacuuming was carried out prior to pillow culture. All were cultured at room temperature, 30 and 37°C for 7 days in broth before plating, and a subset were also cultured for 24 h in broth and then plated. Fungi were identified by standard morphological methods. Results: The commonest three species isolated were Aspergillus fumigatus (n = 10), Aureobasidium pullulans (n = 6) and Rhodotorula mucilaginosa (n = 6). Another 47 species were isolated from pillows and vacuum dust. The number of species isolated per pillow varied from 4 to 16, with a higher number from synthetic pillows. Compared with the nonallergenic A. pullulans, more A. fumigatus was found in synthetic than feather pillows. Conclusions: We have examined pillows for fungal contamination, and show that the typical used pillow contains a substantial load of many species of fungi, particularly A. fumigatus. Given the time spent sleeping, and the proximity of the pillow to the airway, synthetic and feather pillows could be the primary source of fungi and fungal products. This has important implications for patients with respiratory disease, and especially asthma and sinusitis. Copyright © Blackwell Munksgaard 2005.