AbstractCor triatriatum dexter is a rare congenital anomaly in which an obstructive membrane is located in the right atrium. The detection usually occurs after the sequelae of systemic congestion, coagulopathy, and hepatic dysfunction have set in, leading up to a high surgical risk. A percutaneous balloon correction of cor triatriatum dexter in a patient with advanced right‐sided congestive symptoms and hepatic dysfunction is presented. This efficacious method is an alternative to surgical correction and could be extended to the more common cor triatriatum sinistra.