We carried out a survey in 16 libraries of the University of Modena, Northern Italy, to assess the indoor exposure to volatile organic compounds (VOCs), including formaldehyde, and total dusts. Data were collected on the main structural characteristics of the buildings; indoor microclimate parameters, such as temperature, relative humidity and ventilation rate were measured and air samples taken inside and outside the libraries. The mean value of total dusts was 190 +/- 130 microg/m3 with a wide range of values. Formaldehyde was found in only ten out of 16 libraries and the indoor concentrations ranged from 1.70 to 67.8 microg/m3 with an average value of 32.7 +/- 23.9 microg/m3. On the whole, VOCs were present in all the libraries investigated with an average value was 433 +/- 267 microg/m3 (range 102-936 microg/m3). No correlation was found among VOCs, formaldehyde and total dusts nor was a significant association observed with microclimatic parameters or the structural characteristics of the buildings. The general situation found in this study suggests no major problems related to indoor pollution. However, some of the pollutants investigated such as total dust and total VOCs deserve further investigation. It is important to identify the possible sources of contaminants and to define the relationship between indoor and outdoor levels of pollutants more accurately, taking into account the effects of air recycling due to natural ventilation systems.