It has long been known that cooking can create high concentrations of aerosol indoors. Increasingly, it is now being reported that cooking aerosol is also a significant component of outdoor particulate matter. As yet, the health consequences are unquantified, but the presence of well known chemical carcinogens is a clear indication that cooking aerosol cannot be benign. This review is concerned with current knowledge of the mass concentrations, size distribution and chemical composition of aerosol generated from typical styles of cooking as reported in the literature. It is found that cooking can generate both appreciable masses of aerosol at least within the area where the cooking takes place, that particle sizes are largely within the respirable size range and that major groups of chemical compounds which have been used to characterise cooking aerosol include alkanes, fatty acids, dicarboxylic acids, lactones, polycyclic aromatic hydrocarbons, alkanones and sterols. Measured data, cooking emission profiles and source apportionment methods are briefly reviewed.