A crude oil feedstream is treated to remove or reduce the content of known undesired heteroatomic and polynuclear aromatic compounds containing nitrogen and sulfur by contacting the feedstream with one or more solid adsorbent materials selected from attapulgus clay, alumina, silica gel and activated carbon in a mixing vessel for a time that is sufficient to optimize the adsorption of the undesired compounds from the crude oil, subjecting the mixture to atmospheric flash distillation and then to vacuum flash distillation to recover presorbed boiling ranges of products having a lowered content of the undesired compounds, and preferably regenerating at least a portion of the solid adsorbent material for reuse in the process.