The major purpose of the present research is to estimate and compare several measures of race-occupational differentiation across American cities and to examine their relationships to structural and compositional characteristics of cities, especially to the size of the Black population. Using the 1990 PUMS for American cities (MSAs), we estimated measures of nominal segregation and ordinal inequality that were used in past research. The measures used in our analysis include the index of dissimilarity, size standardized index of dissimilarity, index of net differences, and the ratio index that was proposed recently in the literature. The findings reveal considerable differences between the standardized and unstandardized measures. The meaning of the findings and their implications for theoretical conclusions are discussed.