OBJECTIVES: To determine whether parents who use a low literacy, pictogram- and photograph-based written asthma action plan have a better understanding of child asthma management compared to parents using a standard plan. METHODS: Randomized controlled study in 2 urban pediatric outpatient clinics. INCLUSION CRITERIA: English/Spanish-speaking parents of 2-12 year old asthmatic children. Parents were randomized to receive a low literacy or standard asthma action plan (American Academy of Allergy, Asthma and Immunology) for a hypothetical patient on controller and rescue medications. A structured questionnaire was used to assess whether there was an error in knowledge of 1)medications to give everyday and when sick, 2)need for spacer use, and 3)appropriate emergency response to give albuterol and seek medical help. Multiple logistic regression analyses performed adjusting for parent age, health literacy (Newest Vital Sign); child asthma severity, medications; site. RESULTS: 217 parents were randomized (109 intervention;108 control). Parents who received the low literacy plan were 1)less likely to make an error in knowledge of medications to take everyday and when sick compared to parents who received the standard plan (63.0 vs. 77.3%, p = 0.03; adjusted odds ratio [AOR] = 0.5[95% CI: 0.2-0.9]) and 2)less likely make an error regarding spacer use (14.0 vs. 51.1%, p<0.001; AOR = 0.1[0.06-0.3]). No difference in error in appropriate emergency response was seen (43.1 vs. 48.1%, p = 0.5). CONCLUSIONS: Use of a low literacy written asthma action plan was associated with better parent understanding of asthma management. Further study is needed to assess whether use of this action plan improves child asthma outcomes.