The formation of nitrated pyrenes was investigated on nine metallic oxides as soil components with pyrene and various nitrogen sources under xenon lamp irradiation. The metallic oxides studied were CaO, Al₂O₃, MgO, Fe₂O₃, SiO₂ (quartz, silicic anhydride, and silica gel forms), and TiO₂ (rutile and anatase forms). Nitrated pyrene as a reaction product was extracted with benzene: ethanol (4 : 1, v/v) and analyzed by GC/MS selected ion monitoring (SIM). In the presence of indoor air, 1-nitropyrene (1-NP) was produced in all nine metallic oxides, and the yield of 1-NP was high on silicon dioxide (SiO₂; silicic anhydride and silica gel forms) and titanium dioxide (TiO₂; rutile and anatase forms). 2-Nitropyrene (2-NP) and 4-nitropyrene (4-NP) were produced in aluminum oxide (Al₂O₃), magnesium oxide (MgO), and TiO₂ (rutile form). In the presence of nitrogen dioxide gas (NO₂ gas), nitrite ion (NO₂^-) or nitrate ion (NO₃^-), 1-NP was produced in SiO₂ (silicic anhydride and silica gel forms), TiO₂ (rutile and anatase forms), Al₂O₃, and MgO. 2- and 4-NP were produced in most samples of Al₂O₃ and MgO. Accordingly, NO₂ gas, NO₂^-, and NO₃^- were shown to be nitrogen sources for the formation of nitrated pyrenes in these metallic oxides. In addition, in the presence of these nitrogen sources, 2- and 4-NP were produced on metallic oxides as soil components. The yields and formation patterns of the three types of mononitrated pyrenes differed in the various metallic oxides, as well as with the type of nitrogen source (NO₂ gas, NO₂^- or NO₃^-). Hence, the nature of the photochemical reaction in the formation of the nitrated pyrenes differed depending on the type of metallic oxide and source of nitrogen. The yields of nitrated pyrenes depended on the amount of NO₂^- in Al₂O₃ and MgO and on the amount of NO₃^- in Al₂O₃ and SiO₂ (silicic anhydride form). In these experiments, dinitropyrenes were not detected in all cases.