Asthma 1-2-3 is a newly-developed low-literacy multimedia education tool designed to promote asthma self-care concepts among African American adults. An expert panel (n = 10) informed content development for the tool. The video script and storyboard imagery were shown to 30 African Americans recruited from the American Lung Association, whose reactions and comments guided further revisions. The final version was pilot tested in three diverse community settings in Chicago to determine the efficacy of Asthma 1-2-3 at improving patient understanding of asthma and its symptoms. In all, 130 adults participated in the pilot test. Knowledge scores significantly improved from pretest to posttest following presentation of the developed tool for subjects across all literacy levels (Pretest: Mean = 4.2 [SD = 1.6]; Posttest: M = 6.8 [SD = 2.0], P < 0.001). Symptom pathophysiology concepts were the least understood. Individuals with low literacy had less total knowledge score gains compared to those with marginal and adequate literacy (1.8, 2.6, and 3.2 respectively; P = 0.002). The multimedia tool significantly improved understanding of asthma. Individuals with limited literacy may require additional instruction, repeated viewing, or added tangible cues (i.e. supplementary print materials) to support knowledge retention. In general, feedback from the target population was particularly helpful in the development of the tool and its initial evaluation, and should be considered as a necessary step in the creation of other patient education materials.