ABSTRACT Background: Temporomandibular dysfunction (TMD) is a major and complicated health problem affects 20-25% of the population that affects the temporomandibular joint (TMJ) and muscles of mastication, resulting in pain and disability. Objective: to investigate the effect of TMD on cervical retractor muscles maximum isometric strength among adults. Methodology: Twenty-two participants of both genders with moderate to severe disc displacement TMDs diagnosed according to revised Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) algorithm (group A) and 22 healthy subjects (group B) who had no problems in the TMJ or facial pain. The pain intensity was assessed by the Arabic version numerical pain rating Scale and the Lafayette Hand held dynamometer was used to assess the isometric muscle strength. Results: There was a statistically significant difference between the two groups in the mean value of retractors' force; the disc displacement group had lower retractor strength. Conclusion: There is a significant effect of the disc displacement temporomandibular dysfunction on the strength of cervical retractors.