High wax content of crude oil appears to be an original characteristic related to genetic environment or to the kind of organic matter from which the oil was derived. A review of the distribution of probable high-wax crudes throughout the world indicates that they are restricted largely to certain stratigraphic sequences and certain regions. These stratigraphic sequences in large part have in common the following: (1) shale-sandstone (as opposed to carbonate) lithology; (2) nonmarine origin or origin in waters of less-than-normal-marine salinity; (3) common association with coal or other highly carbonaceous strata; (4) stratigraphic range from Devonian to Pliocene, inclusive; (5) continental, paralic, or nearshore-marine environment; (6) association with low-sulfur (rathe than high-sulfur) crudes. Subject to more complete and authoritative data on the worldwide occurrences of high-wax crudes, it appears reasonable to suggest that high-wax oils may reflect the contribution of terrigenous organic matter (or of organic matter derived from aquatic organisms associated with waters of less-than-normal-marine salinity) to the genesis of petroleum.