Cardiac myosin-binding protein C (cMyBP-C) is a component of the thick filaments of the sarcomere. Understanding the structural and functional role of cMyBP-C in the heart is clinically relevant since cMyBP-C gene mutations are a widely recognized cause of hypertrophic cardiomyopathy (HCM), which affects 0.2% of the general population. Nonsense and frame shift mutations are common in cMyBP-C and their expressions are regulated by three quality control systems, the nonsense-mediated mRNA decay, ubiquitin–proteasome system, and autophagy, which contribute to minimize the production of potential poison mutant proteins. This review discusses the structural and regulatory functions of cMyBP-C, the molecular mechanisms involved in cMyBP-C-related HCM, as well as potential causative therapies for HCM.