Important high molecular weight hydrocarbons present in petroleum are commonly referred to as petroleum waxes. The paraffin deposition caused by this class of compounds in pipelines results in a gradual decrease of flow rate and therefore in equipment damage, which increases the costs of oil production. These compounds typically extend to about C-70 in most types of petroleum. One of the most effective analytical methods for characterization of high molecular weight paraffins in petroleum is high-temperature gas chromatography (HT-GC). The present investigation is focused on the optimization and application of a high-temperature comprehensive two-dimensional gas chromatographic (HT-GC x GC) method, with flame ionization detection (FID) and time-of-flight mass spectrometry (TOFMS) for the quantitative and qualitative analysis of Brazilian whole crude oils. A set of fourteen crude oils, including three from the pre-salt layer, were studied. The contents and distribution characteristics of high molecular weight paraffins in various crude oils were summarized. Linear paraffins in the range of C-16-C-60 were detected and identified while maintaining the efficiency of the chromatographic separation. iso-Paraffin and naphthene compounds in the range of C-17-C-60 were also identified and quantified in these crude oils.