A case of bilateral pinnal hamartoma was described in a 3.5-month-old female Brown Swiss calf. There was a bilateral, tumor-like folds causing obstruction of external auditory meatus without further involvement of auditory meatus inside the pinnal surface. There was no signs of pathological discharge or infection. Hinz method was performed for the opening of the external ear canal. During the operation, the masses could not be removed completely, and it was determined that this would not be possible without total extirpation of the external ear pinna. With the request of the owner, the mass was not removed totally. Histopathologic examination revealed a dermal nodule consisted of excessive collagen blending into the surrounding dermis. Collagen fibers were disorganized and thinner compared to the normal pinna. Fusiform fibrocytes were embedded between collagen fibers. Hair follicles were compressed or atrophied, and the epidermis was mildly elevated. Spindle cells were embedded in collagen fibers together with focal hemorrhage and adipose tissue.

External auditory canal preserved its normal condition during 3 month period after the operation. During this period, no increase in the size of the mass was detected, and the animal continue normal life.

In this case report, it is thought that bilateral external ear pinnal hamartoma which have not been reported before in calves have been identified and contributed to the literature.