Sarcoidosis is a multisystem granulomatous disorder with unknown etiology that can affect any organ system. A cardiac involvement is one of the least common manifestations among them. Myocardial sarcoidosis can lead to death. Clinical signs of cardiac involvement can be the first presentation of systemic sarcoidosis. In young or middle-aged patients presenting with conduction abnormalities cardiac sarcoidosis should always be included in the differential diagnosis. In our present case, the cardiac symptom such as arrhythmia was preceded before diagnosing the involvement of the lung or other organs. The other symptoms such as weakness, uveitis, or anemia were not observed except arrhythmia. Here, we report a 51-year old male patient with complete atrioventricular block and pacemaker implantation due to cardiac sarcoidosis, which was unsuccessfully diagnosed.