Patients have diverse beliefs about asthma medications that may be influenced by asthma characteristics. The objective of this qualitative analysis was to identify patients' beliefs about asthma medications and to assess these beliefs according patient and asthma characteristics, including asthma severity and patient-reported medication adherence. From interviews with 52 patients (mean age 43 years, 87% women, 71% taking maintenance medications), 17 categories of beliefs about medications were discerned which were grouped into perceived benefits (e.g., permit activities, thwart symptoms) and perceived drawbacks (e.g., establish a medication routine, ensure supply). Beliefs were not mutually exclusive, with 56% of patients citing both benefits and drawbacks. Beliefs did not differ based on asthma severity or type of current therapy, however, patients who cited drawbacks were more likely to have worse self-reported Morisky Medication Adherence Questionnaire scores (possible range 0-4, higher is worse adherence) compared to those who did not cite drawbacks (1.9 +/- 1.3 vs 0.9 +/- 0.9; p = .02). Providers should be aware of patients' beliefs about medications in order to reinforce perceived benefits and address perceived drawbacks.