In Japan the majority of sarcoidosis-related deaths are due to cardiac sarcoidosis. One of the most common electrocardiographic abnormalities in patients with this disease is atrioventricular block. This study surveyed the incidence of cardiac sarcoidosis in Japanese patients (40 men and 49 women; mean age, 69.1 years) with high-degree atrioventricular block who were admitted to the hospital to receive a permanent pacemaker. We excluded cases in which sarcoidosis had been diagnosed from the involvement of other organs. Patients with the characteristic signs of sarcoidosis underwent echocardiography, radionuclide imaging, and biopsy. Ten cases (11.2%) of cardiac sarcoidosis were diagnosed, most frequently in women aged 40 to 69 years (8 of 25, 32%). Thus the possibility of cardiac sarcoidosis should be carefully considered in middle-aged or elderly Japanese women who show high-degree atrioventricular block.