We report a case of unintentional intraoperative awareness during sevoflurane-remifentanil anesthesia in a 26 years old woman undergoing elective minimal invasive mitral valvuloplasty. Cardioprotective effects of sevoflurane were clinically most apparent when administered throughout the surgical procedure. Also use of sevoflurane during cardiopulmonary bypass decreases incidence of awareness. Although awareness during cardiac anesthesia has been previously described with sevoflurane, the implication of this case is that unexpected awareness can occur in patients with sevoflurane during cardiopulmonary bypass on cardiac surgery. Therefore, more attention is needed to use sevoflurane during cardiopulmonary bypass.