A qualitative and quantitative study is made of the polycyclic aromatic hydrocarbons (PAH), nitrogen oxide, and sulfur dioxide in the atmosphere of the city of Valencia for the period 1988-1989; an analysis is made of their concentrations during the year in terms of season and noise levels. Eleven sampling points in the city were used to determine PAH composition by reverse-phase, high-resolution liquid chromatography with fluorimetric detection, employing an acetonitrile-water gradient; nitrogen oxides and sulfur dioxide were determined by the Valencia city government. Environmental noise levels were determined using a BK 2221 integrated precision sonometer, and temperature values were obtained from the city Meteorological Institute. Daily PAH values varied between 0.1769 and 2.0916 micrograms/m3, whereas the figures for nitrogen oxide were between 91.5 and 100.67 micrograms/m3 during 1982-1989 (only one value, 58.01 micrograms/m3, is available for 1988-1989, corresponding to the Mercadona sampling point), and between 17.33 and 129.36 micrograms/m3 for sulfur dioxide for a total of 9 sampling points; the highest concentrations were recorded in the winter and spring months, the association between PAH and temperature being statistically significant (p less than or equal to .05). The relation to noise was also significant (p less than or equal to .005), Fluoranthene was the predominant PAH in all samples analyzed.