A 2.3 kg partially ossified fibroma developed apparently within a 4½ month period near a tag inserted in the right ear of a 5½ year old white-tailed doe (Odecoileus virginianus). This growth caused an abnormal head carriage, disturbed feeding and resulted in emaciation. Secondary partially ossified fibromas developed at the left ear tag and in the right external acoustic meatus. The latter fibroma penetrated the tympanic membrane. The puncture wounds in the ears associated with the aluminum tags probably provided sites for virus infection and subsequent fibromatosis.