Purpose: Besides depression and anxiety, recently pain catastrophizing has been emphasized for an important psychological factor explaining pain response in various pain conditions including temporomandibular disorders (TMDs). The aims of this study were to evaluate pain catastrophizing of TMD patients and to investigate how the level of pain catastrophizing related with clinical variables and psychometric morbidity. Methods: Inclusion criterion was all new TMD patients ${\geq}18$ years old attending the Department of Orofacial Pain and Oral Medicine of Dankook University Dental Hospital (Cheonan, Korea) over three-month period in 2014, who completed questionnaires. The questionnaires included the Brief Pain Inventory (BPI), Pain Catastrophizing Scale (PCS), and Symptom Check List- 90-Revised (SCL-90-R). All of them were examined clinically and diagnosed. Results: One hundred fifty five patients diagnosed as TMDs were participated in this study (mean age of $38.7{\pm}15.2$ years, male:female=1:2.5). Mean PCS score of the patients was 17.3 with standard deviation of 12.6. By the median of the PCS score (i.e., 15), the subjects were categorized into the high (${\geq}15$) and low catastrophizers (<15). Increased pain severity and interference and increased score of psychological features of SCL-90-R were found in the TMD patients with higher level of catastrophizing (p<0.001) and there was weak to moderate correlation between those factors (p<0.05). Difference in catastrophizing level was not found for other variables such as age, gender, duration of pain, education level and types of TMDs. Conclusions: Conclusively, pain catastrophizing of TMD patients relates positively to pain severity and pain interference. In addition to depression and anxiety, pain catastrophizing is positively correlated with variable other psychological morbidity such as somatization, obsessive- compulsive, interpersonal sensitivity, paranoid ideation and psychoticism. Types of TMD diagnosis do not seem to affect catastrophizing level. The results of this study suggest that pain catastrophizing should be emphasized and assessed in the TMD patients.