The overall incidence of pediatric cardiomyopathy is estimated to be approximately 1–1.5 cases per 100,000 patients. The majority are due to dilated cardiomyopathy, which accounts for more than 50% of all cases. Hypertrophic cardiomyopathy is the second leading cause, with restrictive cardiomyopathy being the least common. While distinct classifications exist, in practice the variants occur in combination. However, there is generally a predominant phenotype diagnosed by echocardiography that allows for the formation of multicenter registries to track the epidemiologic, management, and outcomes related to pediatric cardiomyopathy. This chapter focuses on mixed hypertrophic and restrictive forms of cardiomyopathy and discusses the perioperative management of a patient with mixed cardiomyopathy.