In a given week, a cough and cold medication was used by 10.1% of US children. Exposure was highest to decongestants (6.3%; mostly pseudoephedrine) and first-generation antihistamines (6.3%; most common were chlorpheniramine, diphenhydramine, and brompheniramine), followed by antitussives (4.1%; mostly dextromethorphan) and expectorants (1.5%; almost exclusively guaifenesin). Multiple-ingredient products accounted for 64.2% of all cough and cold medications used. Exposure to antitussives, decongestants, and first-generation antihistamines was highest among 2- to 5-year-olds (7.0%, 9.9%, and 10.1%, respectively) followed by children who were younger than 2 years (5.9%, 9.4%, and 7.6%, respectively); expectorant use was low in all age groups. The use of cough and cold medications declined from 1999 through 2006.