As our ability to diagnosis cardiomyopathy matures and genetic testing becomes more widespread, there has been an increase in the number of children followed for cardiomyopathy. The purpose of this study was to compare health-related quality of life (HRQoL) between children with cardiomyopathy and healthy controls and with children seen in clinic who are at risk for the development of cardiomyopathy. Patient and parent-proxy perspectives were obtained using the Pediatric Quality of Life Inventory (PedsQL^TM) 4.0 Core Scales (ages 2–18 years) and the disease-specific Cardiac Module. Cardiomyopathy physicians’ perceptions of the impact of cardiomyopathy on the functional status of the patients were collected. In addition, data regarding disease-specific medical and socioeconomic information were collected from chart review and parental report. The questionnaires were completed by 100 parent-proxies and 71 children. The PedsQL^TM scores reported by children and their parent-proxies were compared to scores reported by pediatric norms. Compared to healthy controls, patients followed in a pediatric cardiomyopathy clinic scored lower in Total score when compared to pediatric norms (80.7 vs 86.4, p = 0.002). Interestingly, children with a family history of cardiomyopathy who are at risk for developing the disease scored similar to those children with a diagnosis of cardiomyopathy. Parental and patients perceptions were discrepant when compared, which may deter appropriate referral to behavioral health services. These results should encourage cardiomyopathy clinics to screen all patients for HRQoL impairments and to have behavioral services available to assist these children.