OBJECTIVE: Emotional dysregulation, often presenting as severe emotional outbursts, is being increasingly recognized as a source of considerable impairment for individuals with attention-deficit/hyperactivity disorder (ADHD). The aim of this study was to conduct a secondary analysis of data examining the impact of standing stimulant medication on the duration of emotional outbursts. METHOD: The as needed (PRN)-medicated outbursts of psychiatrically hospitalized children, 5 to 12 years of age, were tracked by psychiatric nurses using the Behavioral Activity Rating Scale from the time of PRN administration until the child became calm. The impact of extended-release (ER), immediate-release (IR) stimulant and dose, type and reason for outburst/PRN (aggression, agitation, distress), standing concomitant psychotropic medications and time of day, and days since admission were examined. RESULTS: Forty-seven children had a total of 405 outbursts, 96 of which occurred when no stimulant was prescribed and 309 with stimulant medication. Controlling for time of day and standing neuroleptic dose, outbursts that occurred on an ER stimulant medication were statistically significantly shorter than those that occurred on no stimulant by about 20 minutes (52.7 vs 72.4 minutes), or 30 minutes for aggressive outbursts. Results were unchanged when further controlling for stimulant type and dose, α-agonist, days since admission, PRN medication type, or reason for PRN/outburst. Immediate-release stimulants and short-acting stimulants did not shorten outburst duration. CONCLUSION: In children with ADHD with severe outbursts, ER stimulants were associated with shorter outburst duration than IR stimulants.