This article discusses the application of comprehensive two-dimensional gas chromatography (GC x GC) to samples derived from petrochemicals. The use of GC x GC for characterization of petroleum and petroleum derivatives, through group type analysis, such as benzene, toluene, ethylbenzene, xylenes (BTEX), total aromatic hydrocarbons, polyaromatic hydrocarbons, and heteroatomic sulfur-, oxygen-, and nitrogen-containing compounds is presented. The capability of GC x GC to provide additional chemical-specific information regarding petroleum-processing steps, such as linear alkanes dehydrogenation, Fischer-Tropsch process, hydrogenation and oligomerization, is also described. In addition, GC x GC analyses of petrochemical biomarkers and environmental petrochemical-derived pollutants are reported. The role of comparison of samples through use of simple fingerprint approaches is highlighted.