Aggravation of mitral regurgitation (MR) due to left ventricular outflow tract obstruction (LVOTO) is likely to occur during liver transplantation in cirrhotic patients with hypertrophic cardiomyopathy (HCMP). Moreover, calcium administration following severe hypocalcemia due to inadequate citrate metabolism and massive transfusion may induce MR aggravation with LVOTO in such patients. Herein we have described a cirrhotic patient with HCMP in whom MR was aggravated due to LVOTO resulting from inadvertent rapid administration of calcium during liver transplantation.