Trends in Black infant mortality rates from 1982 through 1991 in large US metropolitan statistical areas were examined.

In some least-segregated areas, the total Black infant mortality rate reached a low of 13 per 1000 live births in 1985 ; it increased sharply after 1985 in the West but not in the South.

The explanation for these trends is unknown, but variation in regional trends in Black postneonatal infant mortality rates suggested that social and medical-care differences among Blacks should be examined.

A high Black infant mortality rate for a group of most-segregated metropolitan statistical areas persisted and contributed to the rising Black-White ratio of rates.