Genotoxicity experiments with exfoliated nasal mucosa cells are a promising minimally invasive approach for the detection of DNA-damaging compounds in ambient air. Results of single cell gel electrophoresis (SCGE) assays with individual cells and organ cultures from bioptic material show that DNA damage caused by compounds such as nitrosamines, polycyclic aromatic hydrocarbons and pesticides can be detected. Biochemical studies indicate that enzymes involved in the metabolism of environmental mutagens are represented in nasal cells. Several protocols for experiments with nasal cells have been developed and it was shown that formaldehyde, metals, styrene and crystalline silica induce DNA damage in SCGE and/or in micronucleus studies; furthermore, it was also found that polluted urban air causes DNA instability in nasal epithelial cells. Comparisons of these data with results obtained in lymphocytes and buccal cells indicate that nasal cells are in general equally sensitive. Broad variations in the baseline levels, differences of results obtained in various studies as well as the lack of information concerning the impact of confounding factors on the outcome of experiments with these cells indicate the need for further standardisation of the experimental protocols.