Hamartoma has been considered rare disease as a congenital malformation of a tumorous lesion since the original description by Albrecht in 1904. Pulmonary hamartoma is interesting to chest surgeon because of good result by surgical procedures and of slightly high incidence then another organs. It is characterized as lesion of very slow growing mass as peak incidence of age of 50 years age group and as sex ratio is 2:1. Especially endobronchial hamartoma is rarer than peripheral type. We had experienced a case of endobronchial hamartoma who has 53 years old male patient at right main bronchus and then treated by excision of tumor mass through right bronchotomy and preserving right lung except any lobectomy and pneumonectomy.[KTCS 1983;1:146-152]