A 5-year-old mongrel male dog with severe left forelimb lameness was referred to the veterinary clinic of Urmia University. On initial physical examination, vital signs were normal. However, a firm swelling with a history of one year progressive increasing in size was observed on the caudolateral aspect of the left shoulder. Pedal reflex was negative. On radiographic examination, a large mass with abnormal radiodensity was seen in the caudal humerus. Hypodermic needle aspiration specimen were unremarkable except large number of normal blood cells. Under general anesthesia, the tumoral mass was surgically removed via a caudolateral approach to the humerus. Pathological assessments corroborated the lobular pattern with the presence of tumor cells similar to normal chondrocytes in an amorphous, basophilic matrix that confirmed the chondroma tumor. In the postoperative follow-up, normal nerve function was returned and lameness was disappeared. Chondroma tumors should be considered in the differential diagnosis of dogs with persistent lameness and neuropathies.