Tako-tsubo cardiomyopathy (TTC) is transient acute cardiac dysfunction, occurring predominantly in postmenopausal women and triggered by an emotional or physical stress. Although it is considered an acquired form of cardiomyopathy, TTC has been sporadically reported to occur among relatives. We report a case of TTC occurring in two sisters. The patients had different triggers and similar ventricular contraction patterns (apical akinesis). Endothelial dysfunction was documented in both patients during hospitalization and it was recovered at the follow-up visit after 6 months.. This finding supports the hypothesis that a genetic predisposition to develop TTC may exist. This could explain why only a small minority of post-menopausal women with emotional stress develops the cardiomyopathy.