Studies of the health status of homeless people have primarily focused on alcoholic men and have reported numerous excess health risks. To determine the health status of children in homeless families, we performed a population-based, cross-sectional survey of a probability sample of 82 homeless families having a total of 158 children 17 days to 17 years of age living in emergency shelters in King County, Washington. Heights and weights were also measured. Seventy-five percent of the children belonged to racial minorities, and 54% were less than 6 years old. Nearly half the children (49%) had a wide variety of reported acute and chronic health problems. Less than 10% of the children measured were short for their age or underweight, whereas 35% were greater than the 95th percentile for weight-for-height. When compared with the US general pediatric population, the proportion of homeless children reported to be in "fair" or "poor" health was four times higher (13% v 3.2%). Thirty-five percent of the children had no health insurance, and 59% of the children had no regular health care provider. The homeless children used emergency rooms at a rate that was two to three times higher than the US general pediatric population (480/1,000 homeless children for 6-month period v 254/1,000 US children for 12-month period), twice as likely to lack measles immunization (21% v 9.0%), and twice as likely to never have had a tuberculosis skin test (48% v 27%). The data suggest that children in homeless families have poorer reported health status and are not obtaining preventive medical care.