The purpose of this study is to investigate the diagnostic accuracy of magnetic resonance arthrography (MRAr) on the diagnosis of intraarticular adhesions of the temporomandibular joint (TMJ). Twenty-four patients (31 joints) diagnosed as internal disorders of TMJ were examined to establish the presence, suspicion or absence of intraarticular adhesions through MRAr according to the MRAr radiographic criteria in a blind fashion, subsequent arthroscopy were performed on all 31 joints. The findings were compared to MRAr with those of arthroscopy. The comparison data were assessed by generating receiver operating characteristic curve (ROC curve) and analyzing the area (Az) under the curve with SPSS11.0 software. The area under the ROC curve was 0.91 (0.86, 0.95), P<0.05. MRAr proves to be an excellent modality to diagnose intraarticular adhesions of TMJ.