The ability of time-of-flight (TOF) mass spectrometry using an ultrahigh resolving power (R-p of 100 000 at m/z 400) analyzer (HRT) to provide a proper platform for comprehensive petroleomic studies has been evaluated. The innovative HRT design for ultrahigh resolution using a "zig-zag" multi-reflecting analyzer with a folded flight path, efficient ion refocusing, and no substantial loss of ion transmission was tested. For comparison, samples were also analyzed by Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) using variable R-p (from 100 000 at m/z 400 to 400 000 at m/z 400). Both HRT and FT-ICR MS data were processed and compared using software specifically designed to process either TOF or FT-ICR data for petroleomic studies. Owing to the increase in R-p with m/z, the 100 000 at m/z 400 R-p of the HRT is found to be, overall, comparable to that of a 200 000 at m/z 400 FT-ICR. This R-p is sufficient to allow for proper resolution, correctly resolve most isobaric interferences, and accurately measure m/z values, leading to proper characterization of petroleum components via assignments of molecular formulas and classes. Results using electrospray ionization (ESI) focus on polar components, and their molecular formulas were properly translated to heteroatom classes, unsaturation levels measured via double bond equivalents (DBEs), and carbon number, which were displayed via classical geochemical plots. Data have shown that the compositional information provided by HRT is comparable to FT-ICR for most operational routine analyses. HRT operating with a R-p of 100000 at m/z 400 was therefore found to offer a fast, accurate, sensitive, and cost-effective platform suitable for accurate petroleomic MS fingerprinting of crude oils and distillates.