['Medline, Embase and the Chinese Biomedical Literature databases were searched with no language restrictions.', 'Studies evaluating the diagnostic efficacy of ultrasonography in detecting TMJ disc displacement in participants with any symptoms or clinical signs related to temporomandibular disorders (TMD), with use of MRI as the gold standard, were included.', 'Study selection, data abstraction and risk of bias assessment were carried out independently by two reviewers. A meta-analysis was conducted.', 'Fifteen studies (14 cohort studies and one case control) were included in this review; six studies had a low risk of bias, six studies an unclear risk and three studies a high risk. Meta-regression indicated that the detected results were not influenced by the types of ultrasonography, image dimensions, types of transducer and ultrasonic image of the disc (P= .05). The Q* values (the point where sensitivity equals specificity on the summary reviewer operator characteristics curve) of ultrasonography for the closed- and open-mouth positions were 0.79 and 0.91, respectively. The diagnostic efficacy of disc displacement with reduction had a sensitivity of 0.76, a specificity of 0.82, a positive likelihood ratio of 3.80, a negative likelihood ratio of 0.36, a diagnostic odds ratio of 10.95, an area under the curve of 0.83 and a Q* of 0.76. The diagnostic efficacy of disc displacement without reduction had a sensitivity of 0.79, a specificity of 0.91, a positive likelihood ratio of 80.5, a negative likelihood ratio of 0.25, diagnostic odds ratio of 36.80, an area under the curve of 0.97 and a Q* of 0.92.'] Does ultrasonography have an acceptable diagnostic efficacy for temporomandibular disc displacement?