BACKGROUND AND OBJECTIVES: The use of written asthma action plans (WAAPs) has been associated with reduced asthma-related morbidity, but there are concerns about their complexity. We developed a health literacy-informed, pictogram- and photograph-based WAAP and examined whether providers who used it, with no training, would have better asthma counseling quality compared with those who used a standard plan. METHODS: Physicians at 2 academic centers randomized to use a low-literacy or standard action plan (American Academy of Allergy, Asthma and Immunology) to counsel the hypothetical parent of child with moderate persistent asthma (regimen: Flovent 110 mug 2 puffs twice daily, Singulair 5 mg daily, Albuterol 2 puffs every 4 hours as needed). Two blinded raters independently reviewed counseling transcriptions. PRIMARY OUTCOME MEASURES: medication instructions presented with times of day (eg, morning and night vs number of times per day) and inhaler color; spacer use recommended; need for everyday medications, even when sick, addressed; and explicit symptoms used. RESULTS: 119 providers were randomly assigned (61 low literacy, 58 standard). Providers who used the low-literacy plan were more likely to use times of day (eg, Flovent morning and night, 96.7% vs 51.7%, P < .001; odds ratio [OR] = 27.5; 95% confidence interval [CI], 6.1-123.4), recommend spacer use (eg, Albuterol, 83.6% vs 43.1%, P < .001; OR = 6.7; 95% CI, 2.9-15.8), address need for daily medications when sick (93.4% vs 34.5%, P < .001; OR = 27.1; 95% CI, 8.6-85.4), use explicit symptoms (eg, "ribs show when breathing," 54.1% vs 3.4%, P < .001; OR = 33.0; 95% CI, 7.4-147.5). Few mentioned inhaler color. Mean (SD) counseling time was similar (3.9 [2.5] vs 3.8 [2.6] minutes, P = .8). CONCLUSIONS: Use of a low-literacy WAAP improves the quality of asthma counseling by helping providers target key issues by using recommended clear communication principles.