The refugees of Southeast Asia continue to enter the United States in large numbers and have many health care needs. Specific data on normal growth and normative processes are lacking in these diverse cultural groups. Perinatal parameters among Cambodian and Hmong families were studied and compared with those of a Caucasian control group. The birth weight, length, and head circumference were smaller and distributed around different means among both refugee groups, although the ponderal indexes and measures of gestational maturity were the same as the control group. Perinatal complications, including cesarean section rate, were less among the refugee groups. The Cambodian and Hmong women had a higher parity and gravidity. They were shorter and lighter at the onset of pregnancy and their mean total weight gain was less than 10 kg. A substantially higher incidence of infectious disease was present among these groups. Households were large, especially among the Hmong, and the prior birth interval in this group was less than two years.