Patients with cardiac diseases must be carefully evaluated and managed, as manycomplications may set in during or after operations. Dental surgery on 100 patients with cardiac diseases was performed in our institution from 1984 to 1987. Results: (1) 51 percent of the 100 cases were ischemic heart diseases.(2) Electrocardiographic findings before dental surgeries. 34 percent of the findings were normal. 25 percent showed atrial fibrillations, and 17. 1 percent were ST-T changes. (3) Anticoagulant therapy was maintained on 51 patients. 28 patients underwent dental surgery with interrupted anticoagulant therapy and others were performed dental surgery with non-interrupted anticoagulant therapy. (4) Complications during and after dental surgery. In 15 cases, ventricular extrasystole occurred and in 5 cases, systolic blood pressure increased from 200 to 230 mmHg. After dental surgery, we had bleeding problems in 6 cases. But there were no significant complications after careful treatment and management.