Die de-asphalting of vacuum residue of Nigerian medium-gravity crude with nitrobenzene has been studied. Analytical data such as viscosity index, viscosity gravity constant, and molecular weight were used to characterize the residue, while chromatographic analyses of the solvent-free extract and raffinate products provided a measure of nitrobenzene de-asphalting efficiency at different solvent-residue ratios. From these data, it was established that the residue was paraffinic and suitable for lube oil manufacture. At a solvent-residue ratio of 6, a de-asphalted oil yield of more than 70 wt. % was achieved, which is comparable to those often reported for the conventional propane system at relatively higher solvent proportions. In contrast to the observed trend of solubilization power, the selectivity of nitrobenzene toward asphaltic material showed a decrease with increased solvent proportion, resulting in the more desirable raffinate with potentially improved oil composition at lower solvent-residue ratio.