Improving patients’ symptoms, function, and quality of life is the primary focus of treatment for obstructive hypertrophic cardiomyopathy (oHCM). Patients with oHCM may or may not benefit from using the Kansas City Cardiomyopathy Questionnaire (KCCQ), which was valid, reliable, and sensitive for measuring other causes of heart failure. This research aimed to determine whether or not the KCCQ was valid, reliable, and responsive in patients with oHCM. About 26 oHCM patients underwent KCCQ cognitive debriefing. Using a patient-reported global impression (PGIC) of change and comparisons to other scales, researchers compared the KCCQ’s validity, reliability, responsiveness, and interpretability in a sample of 196 people from the EXPLORER-HCM trial. Every section of the KCCQ had statistically significant relationships with other measures of symptoms, function, social limitation, and quality of life, including a newly developed instrument evaluating symptoms that were missed by the KCCQ (P<0.0001). High intraclass correlation coefficients were seen alongside insignificant mean changes of 0.21 to 2.3 points among stable patients (P>0.30 for all). Mean differences of 5-, 10-, and 20- points between individuals with modest, moderate, and significant clinical alterations were consistent with those seen in patients with various causes of heart failure. There was substantial data supporting the KCCQ’s good psychometric performance and patients with oHCM report that it was easy to understand. It may be useful in the therapeutic care of patients with oHCM and can also be used as a relevant outcome in clinical trials of oHCM therapy.