This article investigates the shifting racial and ethnic composition of neighborhoods in the Greater New York metropolitan region in the 1970–1990 period, during which the region has been one of the nation's major receiving grounds for new immigrant groups. Neighborhoods are defined in terms of census tracts, and changes in neighborhood composition are tracked with data from the 1970, 1980, and 1990 censuses. Four racial/ethnic groups are considered: non-Hispanic whites, non-Hispanic blacks, Hispanics and Asians. The analysis, which exploits the neighborhood transition table (Denton and Massey, 1991), reveals a somewhat paradoxical set of developments. On the one hand, there is increasing racial and ethnic complexity in neighborhoods throughout the region: more and more neighborhoods contain multiple groups; fewer and fewer are ethnically or racially homogeneous. On the other hand, there is a crosscutting trend: all-minority neighborhoods, occupied by blacks or blacks and Hispanics, are growing in number. We demonstrate further that these two patterns are associated with other characteristics of neighborhoods, such as the median incomes of their households and whether they are located in cities or suburbs.