Urban scholars and planners look to evidence of recent gains in the number of nontraditional households as a potential source of increase to the population sizes and tax bases of declining central cities. While it is now well established that substantial gains in the numbers of small, nontraditional households have occurred since the 1950s, it has not been demonstrated that: (a) these households are more likely to relocate in the city than traditional family households (husband-wife with children under 18); or (b) their cityward relocation patterns will significantly alter trends toward smaller city household populations. This paper addresses these questions by examining changes in city-suburb migration stream rates by household type over periods 1955-60, 1965-70 and 1970-75 for large metropolitan areas, and assesses their implications for potential changes in the aggregate sizes of city household populations.