Some oil products are known to cause skin tumors following long-term application while others do not. The ability to predict which ones might cause tumors is important. Development of reliable short term tests which can accurately predict tumorigenic potential of oil products is needed to avoid the high cost and long time required for traditional animal bioassays. Several short term tests were evaluated for their ability to predict tumorigenic potential of 10 coded oil samples and results were compared to results of mouse bioassays. Analytical determinations of PAC content (DMSO extraction) and 3-6 ring PAC content were also made for each of the 10 samples for further comparison. Tests which showed good correlation with bioassay results and thus were considered good predictors of tumorigenic potential were: Sustained Epidermal Hyperplasia as measured by epidermal thickness, Nuclear Area of epidermal basal cells, Modified Ames Test and DMSO extraction for PAC content. Tests which did not show good correlation with bioassay results and which were not considered good predictors of tumorigenic potential were: Polymorphonuclear leukocyte (PMN) infiltration into the dermis, Unscheduled DNA Synthesis in epidermal cells and Changes in Nuclear DNA Content of CHO cells.