BACKGROUND Increased asthma morbidity and mortality is associated with inappropriate home self-management skills. OBJECTIVE To examine the proportion of children presenting to the emergency department (ED) with an acute asthma exacerbation with incorrect home use of their albuterol inhaler and to identify factors associated with improper treatment. METHODS Caregivers of children with asthma aged 4 to 14 years, presenting to the ED with an asthma exacerbation, participated in the study. Interviewers collected caregiver's perceived severity of the asthma exacerbation and home albuterol use before the ED visit. National Asthma Education and Prevention Program guidelines were used to classify home albuterol use as appropriate or inappropriate. RESULTS Home albuterol use for the current asthma exacerbation was categorized as inappropriate (56 [68%]) and appropriate (26 [32%]) for 84 participants. Thirty-nine of the inappropriate group undertreated, with 24 not giving albuterol frequently enough and 15 without albuterol at home. Other reasons for incorrect home albuterol use included: no spacer, overtreating, overreacting, and using a controller medicine for quick relief. Those with appropriate albuterol use were more likely to have their child hospitalized for asthma in the past 48 months (P=.004). Caregivers with inappropriate use perceived their child's asthma exacerbation as more severe (P<.001) compared with physician rating. Physicians rated asthma severity higher in the appropriate group than the inappropriate group (P<.001). CONCLUSIONS A significant proportion of caregivers incorrectly treat children's asthma exacerbation with albuterol. Despite perceiving their children's asthma exacerbations as more severe, most undertreat with albuterol. Correctly assessing asthma symptom severity and appropriate home albuterol use may be linked to disease experience.