Elbow arthroscopy was performed in 30 dogs of different breeds. The procedure was performed bilaterally in 20 of these dogs, yielding a total of 50 joints. Different lesions were found, varying from cartilage fissures (8) to fragmentation (42) of medial coronoid process (FCP) of the ulna. Osteochondritis dissecans (OCD) of the humerus medial condyle was associated in four of them. All of these cases displayed varying degrees of synovitis. Osteoarthrosis (OA) in varying intensity was observed in 44 joints. The majority of cases were treated two to four months after the manifestation of clinical signs. Good clinical recovery occurred in dogs with minimal joint lesions, where these were diagnosed and treated within four weeks of the onset of clinical symptoms. Early diagnosis and arthroscopic treatment prevent osteoarthrosis and preserve locomotor function.