OBJECTIVES: The National Lipid Association encourages improved understanding and assessment of patient-reported statin intolerance (SI). We sought to develop a patient-reported outcome questionnaire to assess real-world patient SI experience.  METHODS: Questionnaire development was informed by (1) a literature review (n=41 articles, n=3 drug labels), interviews with expert providers (n=5), and patient concept elicitation interviews (CEIs; n=20); (2) concept selection and questionnaire construction; and (3) cognitive debriefing with experts (n=5) and patients (n=15). Rigorous methodology was employed to identify concepts most relevant to patients experiencing SI and create a content-valid tool for measuring SI-related concepts perceived as useful by patients and providers.  RESULTS: Results identified 3 areas of measurement: SI symptoms, impacts, and medication behavior. Muscle-related symptoms, and associated physical impacts, were commonly reported in the literature (85.4% of articles) and by experts (n=5, 100%). In CEIs, patients with SI also commonly reported muscle-related symptoms (n=17, 85.0%) in addition to non–muscle-related symptoms (n≤3, 15.0%). In the resulting 17-item questionnaire, instructions, items, and response options were positively reviewed by patients and experts during the cognitive interviews but resulted in some modifications and a 15-item questionnaire. Nausea and headache were removed based on irrelevance to SI according to some experts (n=2, 40.0%) and patients (not relevant to 12/15 [80.0%] and 7/15 [46.7%], respectively). The Statin Experience Assessment Questionnaire (SEAQ) assesses the severity and impact of 6 SI symptoms (muscle aches, muscle pain, muscle cramps, muscle weakness, tiredness, and joint pain) on an 11-point numeric scale in the 30 days before assessment. Statin discontinuation and the likelihood of discontinuation due to symptoms are also assessed on yes/no and Likert scales, respectively.  CONCLUSIONS: The SEAQ is a content-valid questionnaire that can be used in clinical settings to facilitate patient/provider communications about SI. Additional research is recommended to validate the SEAQ in real-world settings.