BACKGROUND: In October 2007, manufacturers voluntarily withdrew over-the-counter (OTC) infant cough and cold medications (CCMs) from the US market. A year later, manufacturers announced OTC CCM labeling would be revised to warn against OTC CCM use by children aged <4 years. We determined whether emergency department (ED) visits for CCM adverse drug events (ADEs) declined after these interventions. METHODS: We used National Electronic Injury Surveillance System-Cooperative Adverse Drug Event Surveillance data from 2004 to 2011 to estimate the number of ED visits for CCM ADEs before and after each intervention. RESULTS: Among children aged <2 years, ED visits for CCM ADEs decreased from 4.1% of all ADE ED visits before the market withdrawal to 2.4% of all ADE visits afterward (difference in proportion: –1.7%, 95% confidence interval [CI]: –2.7% to –0.6%). Among children aged 2 to 3 years, ED visits for CCM ADEs decreased from 9.5% of all ADE ED visits before the labeling revision announcement to 6.5% of all ADE visits afterward (difference in proportion: –3.0%, 95% CI: –5.4% to –0.6%). Unsupervised ingestions accounted for 64.3% (95% CI: 51.1% to 77.5%) of CCM ADE ED visits involving children aged <2 years after the withdrawal and 88.8% (95% CI: 83.8% to 93.8%) of visits involving children aged 2 to 3 years after the labeling revision announcement. CONCLUSIONS: After a voluntary market withdrawal and labeling revision, ED visits for CCM ADEs declined among children aged <2 years and 2 to 3 years relative to ADE ED visits for all drugs. Interventions addressing unsupervised ingestions are needed to reduce CCM ADEs.