Female mice of 16 inbred mouse strains were fed an atherogenic diet for 14 weeks and were then evaluated for atherosclerotic lesions in the aorta. Strains C57BL/6, C57BR/cd, C57L, and SM were very susceptible to atherosclerosis, with lesion area/aortic cross-sections in the range of 4500 to 8000 microns 2. Strains C58 and SWR were intermediate in susceptibility, with lesion area/sections in the range of 1670 to 1690 microns 2. Strains 129, AKR, DBA/2, and BALB/c had only small lesions in the range of 20 to 350 microns 2/section; strains C3H, NZB, CBA, HRS, SJL, and A had no lesions after 14 weeks. Lesion formation in five strains was compared at several time points. Strain C57BL/6 mice developed lesions by 7 weeks, and these continued to grow until all mice had large atheromatous plaques in the aorta and coronary arteries. Strains AKR and DBA/2 also had fatty streak lesions as early as 7 or 8 weeks, but these lesions had not progressed in size by 14 weeks. Strains BALB/c and C3H, which were both resistant to lesion formation at 14 weeks, diverged from each other as time progressed. By 1 year, BALB/c mice had large lesions, but C3H mice had none. Most of the inbred strains chosen for evaluation are the progenitors of recombinant inbred sets of strains, a genetic tool that greatly facilitates the analysis of strain differences. This survey indicates seven additional recombinant inbred sets of strains whose progenitors differ in atherosclerosis susceptibility: BXD, AKXL, SWXJ, NX8, 129XB, NXSM, and B6NXAKRN. An analysis of these recombinant inbred strains may reveal additional mouse genes affecting atherosclerosis susceptibility.