•PAHs were detected in the cooking exhaust from the fat-rich food samples.•The major PAHs generated by grilling were phenanthrene, fluoranthene, and pyrene.•The percentage of 5- to 7-rings PAHs increased as the particle diameter decreased.•Most of PAHs generated were concentrated in particles with diameters of <0.43μm.•More than 90% of the PAHs emitted by grilling would reach the alveolar region. The concentration and particle size distribution of 19 major polycyclic aromatic hydrocarbons (PAHs) emitted by thermal cooking were investigated. Corn, trout, beef, prawns, and pork were selected for grilling. The PAHs in the oil mist emitted when the food was grilled were collected according to particle size range and analysed by GC/MS. Much higher concentrations of PAHs were detected in the oil mist emitted by grilled pork, trout, and beef samples, which were rich in fat. The main components of the cooking exhaust were 3- and 4-ring PAHs, regardless of food type. The particle size distribution showed that almost all the PAHs were concentrated in particles with diameters of <0.43μm. For pork, the toxic equivalent of benzoapyrene accounted for 50% of the PAHs in particles with diameters of <0.43μm. From these results, we estimated that >90% of the PAHs would reach the alveolar region of the lungs.