Fifteen patients with intracavitary cardiac tumors were operated on at the Kobe University Hospital between September 1977 and January 1984. Three of the patients were men and twelve were women. They ranged in age from 9 to 75 years. Their symptoms were chest pain, dyspnea, cough, palpitation and syncope. Definite diagnosis was confirmed by echo- and cineangiocardiography. There were 14 benign tumors consisting of 13 myxomas, one leiomyoma and one malignant myxosarcoma. The left atrium was the most common chamber involved (12 instances), followed by the right atrium (3). Surgery was performed in all cases under cardiopulmonary bypass with moderate hypothermia and cold crystalloid cardioplegia. Tumors were removed en bloc at the base with their attachment to the atrial septum or free wall in all cases. Three patients underwent concomitant mitral annuloplasty or mitral commissurotomy. Two cases with left atrial myxoma died postoperatively: one case associated with mitral annuloplasty died of congestive heart failure due to newly developed chordal rupture two months after surgery, and the other died of congestive heart failure 13 months after the first operation. Re-excision for recurrence of the myxosarcoma in the left atrium was performed in the latter case as a second surgical procedure. The remaining 13 cases with benign tumors are doing well and are without recurrence. From these favorable results, surgical intervention should be recommended prior to the occurrence of heart failure and severe complications such as coronary or peripheral embolism whenever cardiac tumors are detected by non-invasive echocardiography and cineangiocardiography.