Buprenorphine in sublingual formulation was recently introduced to the American market for treatment of opioid dependence. We report a series of 5 toddlers with respiratory and mental-status depression after unintentional buprenorphine exposure. Despite buprenorphine's partial agonist activity and ceiling effect on respiratory depression, all children required hospital admission and either opioid-antagonist therapy or mechanical ventilation. Results of routine urine toxicology screening for opioids were negative in all cases. Confirmatory testing was sent for 1 child and returned with a positive result. The increasing use of buprenorphine as a home-based therapy for opioid addiction in the United States raises public health concerns for the pediatric population.