The chapter reports the polyaromatic or heteroaromatic (“sulfur-/nitrogen-containing aromatics”) extraction from diesel fuels through the viable use of deep eutectic solvents (DESs). It gives directions with respect to the use of DESs for potential application in aromatic fuels, particularly “diesel”, while also removing sulfur and nitrogen polyaromatic compounds from aliphatic hydrocarbons. The DESs’ performance was quantified through single-stage liquid–liquid extraction where the liquid–liquid equilibrium data involving extract and raffinate phase is determined. The compositions from the extract and raffinate phases were then ascertained through nonrandom two-liquid, universal quasi-chemical, and conductor-like screening model for real solvents–based models. The extraction mechanism for aromatic compounds was also explored using the nuclear magnetic resonance and Fourier transform infrared analysis. The noncovalent interaction was found to be mainly responsible for the extraction of aromatic or heteroaromatic from the aliphatic mixture. It was concluded that DESs could be considered as potential solvents for the simultaneous dearomatization, desulfurization, and denitrogenation of diesel fuels.