Objective of the study was to compare diagnostic value of 3 different diagnostic modalities of canine TMJ with particular interest to arthroscopy. Material. There were 4 canine heads used for the studies representing following breeds: German shepherd, Bernese mountain dog, Boxer and Labrador retriever. All of them were obtained from the matured dogs euthanised because of healthy reasons and with release of rights of their bodies. Procedures. Three different diagnostic procedures were performed: Standard extra oral radiography, followed by CBCT and finally arthroscopy was performed in both TMJs. After arthroscopy another CBCT was done to evaluate possible damages to evaluated structures. Results Each diagnostic method delivered different range of informations. The most limited diagnostic value provided was standard extra oral radiography. CBCT assessment obtained exact size, shape topography of the TMJ both individual and comparative. Additionally condylar and temporal bone condition assessment was available. During arthroscopy the examiner could evaluate soft tissue like articular disc, joint capsule, articular cartilage surface and content of articular space. In conclusion TMJ diagnostics process can benefit from CBCT and arthroscopy and these two diagnostic modalities are complementary. Standard radiography can play a role as an orientation method only being significantly inferior to two other discussed methods.