The lack of standardized diagnostic criteria for defining clinical subtypes of temporomandibular disorders (TMD) was the main motive to create the Research Diagnostic Criteria for TMD (RDC/TMD), which were provided to allow standardization and replication of research into the most common forms of muscle- and joint-related TMD. The RDC/TMD offered improvement compared to the older literature: the use of one system classifying TMD subgroups and the introduction of a dual-axis classification. The aim of this Focus Article is to appraise the RDC/TMD Axis I (physical findings). Since the original publication in 1992, no modification of the RDC/TMD has taken place, although research has yielded important new findings. The article outlines several concerns, including diagnostic issues in Axis I, classification criteria, feasibility of palpation sites, the myofascial diagnostic algorithm, the lack of joint tests (compression, traction), and missing subgroups. Using a gold standard examiner may improve calibration and offer better reliability; it does not improve any of the diagnostic validity issues. It is also noted that in the 2004 mission statement of the International Consortium For RDC/TMD-Based Research, the RDC/TMD are also advocated for clinical settings. Clinicians may eagerly embrace the RDC/TMD, believing that the clinical use of the RDC/TMD as a diagnostic procedure is already supported by evidence, but its application is not indicated in clinical settings. The article concludes that given the research developments, there is a need to update the RDC/TMD Axis I in the clinical research setting.