Large differences between the age patterns of mortality as reflected in official U.S. life tables exist for whites and Negroes. However, the quality of the data underlying the tables for Negroes may be so defective that it is questionable if these life tables provide an accurate representation of the patterns of mortality actually experienced by Negroes. Alternative hypotheses concerning the differences are examined. However, comparisons of the official life tables after adjustment for major sources of error with model life tables suggest that the age patterns of mortality for American Negroes do in fact differ from those of the whites. This difference implies the need to develop additional families of model life tables.