To define differences in knowledge and attitudes about environmental tobacco smoke (ETS) and smoking among different populations of parents and children, surveys about smoking and health were administered in low-income pediatric clinics and upper-income private practices using a Likert scale. Sixty-five children and 300 parents from pediatric clinics and 149 children and 300 parents from private practices participated. At the clinics 39% of parents were white, 23% graduated college, 33% smoked, and 20% allowed smoking in their home. This differed from private practices where 93% of parents were white, 77% graduated college, 13% smoked and 6% allowed smoking in their home. Parents from private practices expressed greater agreement with fact and opinion statements about ill effects of tobacco. More lower income children reported living with a smoker (45% vs 23%). These data demonstrate differences in adult knowledge and attitudes about health effects of smoking, highlighting the need for increased intervention among lower income families.