Although formaldehyde has recently been classified by the IARC as "carcinogenic in humans" (class 1), it is still widely used in pathology departments for the fixing and conservation of biological tissues. Its use therefore raises the question of occupational exposure. The present paper reports the results of an environmental monitoring campaign to evaluate pollution by formaldehyde in various areas of three pathology departments. Chemi-adsorbent cartridges able to adsorb airborne formaldehyde were used to detect the substance. Quantitative determination of the formaldehyde was carried out by means of liquid chromatography (HPLC). The concentrations of airborne formaldehyde in the areas monitored were fairly modest, being below the limits of indoor concentration proposed by the OSHA. In one of the three departments, however these limits were exceeded in 40% of the samples taken in the room used for the storage of containers. As yet, in spite of the recent class 1 classification by the IARC, no provisions have been made to ban the use of formaldehyde. It is therefore essential to draw up environmental monitoring programmes in order to evaluate occupational exposure and to assess the efficacy of any preventive measures adopted.