Objective: In this study, we aimed to evaluate the properties of temperament and character in patients with social anxiety disorder(SAD) compared to healthy controls, who have similiar socio-demographic characteristics. The secondary aim of study is to investigate the relationship between temperament and character in patients with social anxiety disorder with the presence of comorbid depression and disease severity. Method: This study was conducted at the Outpatient Clinic in the Department of Psychiatry of Sisli Etfal Educating and Researching Hospital. 64 patients with social anxiety disorder whose diagnoses were made by DSM-IV and 64 healthy controls were included in this study. Control group were matched to SAD group according to age, gender and educational status. Cloninger Temperament and Character Inventory, Hamilton Depression Scale and Liebowitz Social Anxiety Scale were administered to the participants. SCID-I/CV (Structured Clinical Interview for DSM-IV Axis I Disorder, Clinical Version) was used to evaluate the psychopathology in patients and control groups. Results: With or without comorbid depression, in SAD group HA(harm avoidance) scores were significantly higher compared to healthy controls and this difference was more pronounced in SAD group with comorbid depression. In addition, P(persistence) score was significantly lower in SAD group with comorbid depression compared to healthy controls while RD (reward dependence) score was significantly lower in SAD group without comorbid depression compared to healthy controls. In terms of character traits, SD(self directedness) and C(cooperativeness) scores were significantly lower in both SAD with or without comorbid depression groups compared to healthy controls. SD (self-directedness) score was significantly lower in generalized SAD group compared to non-generalized SAD group where as HA score was significantly higher in generalized SAD group compared to non-generalized SAD group. It seems that there is a linear relationship between the severity of illness and HA(harm avoidance) scores. Discussion: One of the most important findings of this study is that, HA is not only associated with depression, HA significantly rise in SAD patients without depression. Regardless of other temperament parameters HA has a significant effect on the severity of the SAD, and this supports the hypothesis that the serotonergic system plays a significant role on SAD. [Anadolu Psikiyatri Derg 2015; 16(2.000): 122-129]