When seeking medical care, homeless persons often turn to health centers that were designed to treat the poor who have homes. To provide for effective medical care, personnel in such facilities need to know how the health care needs of the homeless are different from those of other clinic users. To compare the physical health of these two groups, we conducted a health survey and screening physical examination of 464 patients who attended the general adult and homeless clinic sessions of one of the main neighborhood health centers in Los Angeles County, California. As compared with the poor who have homes, homeless persons were more likely to have dermatological problems (32% vs 21%), functional limitations (median, 2 vs 0 per person), seizures (14% vs 6%), chronic obstructive pulmonary disease (21% vs 12%), social isolation, serious vision problems (22% vs 12%), foot pain, and grossly decayed teeth (median, 1 vs 0 per person). We conclude that to care more optimally for homeless adults, health centers must pay attention to their functional disabilities, substance abuse, skin abnormalities, vision impairment, dental problems, and foot problems.