Primary graft dysfunction after heart transplantation is a severe complication generally related to prolonged ischemia time, size mismatch, or poor quality of the organ. Current therapeutic options include pharmacologic inotropic support with catecholamines or phosphodiesterase inhibitors, and mechanical circulatory support. We report 12 patients who received levosimendan, a new Ca(2+) sensitizer, as adjunctive inotropic support. The patients showed a rapid reduction of the doses of inotropic drugs, and no patient needed mechanical support. Levosimendan may be a useful, adjunctive inotropic drug in the treatment of patients with primary graft dysfunction after heart transplantation.