Aim: The aim of this study is firstly to compare the obsessive-compulsive disorder (OCD) patients with good insight and OCD patients with poor insight in terms of socio-demographic and clinical features; to investigate the relation between insight and the level of the expressed emotion (EE) in the patients; and lastly to specify the factors that predict level of insight. Methods: OCD patients with good insight and patients with poor insight were compared in terms of clinical features and the perceived EE level of the patients and the individuals that they live with in order to specify the factors that predict the insight level, and to investigate the relationship between insight level and EE. Results: It was found that the total Expressed Emotion Scale, total Level of Expressed Emotion (LEE), LEE-Emotional Response and LEE-Tolerance/Expectation subscale scores of the group comprised of patients with poor insight are higher than the other group. The results also show that the duration of illness and Yale-Brown Obsessive Compulsive Scale (Y-BOCS) total score predict insight level. Conclusions: This study shows that the level of EE perceived by the patients with poor insight and the person that he/she lives with, is higher than the group with good insight. The studies that investigate the relationship between the factors of insight level and EE level, which are indicated to determine the level of the illness severity and its chronicity, will enable the researchers to understand the importance of the role of the family on the treatment processes of OCD.