A comprehensive examination of a Wilmington, California, crude oil containing appreciable quantities of nitrogen, sulfur, and oxygen compounds as well as trace amounts of porphyries and metals is presented. The nitrogen compounds are mostly high molecular weight materials and form the predominant group in the asphalt. Relatively small amounts can be found in the distillate and even these are in the higher boiling fractions. The compounds are seventy percent non-buric. As only basic compounds have been identified from petroleum, the majority of the Wilmington nitrogen compounds have structures as yet undefined. Pyroles, indoles, and carbazoles are suspected. The sulfur compounds differ from those of previously studied oils in that no thiols. The type sulfur analysis indicates the sulfur compounds as sulfide and include the thiophene compounds in this classification.