This study was conducted to show the relationship between pain catastrophizing and activity pain severity with bite force and jaw muscle strength in individuals with temporomandibular disorders (TMD). Forty-three individuals (mean age 29.79±8.34 years) with a diagnosis of TMER were included in the study. Pain catastrophizing levels of individuals with the Pain Catastrophizing Scale (PCS), activity pain with the Visual Analog Scale (VAS), bite force with a pinch meter, and jaw muscle strength with Lafayette manual muscle testing device were measured. The relationship between the variables was examined with the Pearson Correlation test. Statistically significant negative correlations were found PCS between bite forces (central: -0.519; right: -0.518; left: -0.515) and jaw muscle strengths (opening: -0.688; closing: -0.635; right excursion: -0.609, left excursion: -0.645; protrusion: -0.621); activity pain intensity between bite forces (central: -0.429; right: -0.453; left: -0.451) and jaw muscle strengths (opening: -0.511; closing: -0.420; right excursion: -0.343, left excursion: -0.463; protrusion: -0.471) (p