Background and aim:Pregnancy is a risky period to develop Adult Separation Anxiety Disorder (ASAD). The aim of this study was to investigate the frequency of separation anxiety in pregnant women, and the relationship of separation anxiety with sociodemographic variables and intolerance of uncertainty. Methods:This study included 310 pregnant women and used the Adult Separation Anxiety Questionnaire (ASAQ) and Intolerance of Uncertainty Scale-Short Form (IUS-12). Results:The average age in pregnant women with ASAD was lower. IUS-12 total score, prospective anxiety, and inhibitory anxiety subscale scores were significantly higher in the ASAD group. There were moderate and statistically significant positive correlations between the ASAD score and the IUS-12 total, prospective anxiety and inhibitory anxiety subscale scores. Conclusion:Intolerance of uncertainty may be an important factor in the mental processes of individuals with separation anxiety. Pregnancy period can be a risky period for developing ASAD. Cognitive behavioral treatments including intolerance of uncertainty may be effective in the treatment of ASAD. There is a need for follow-up studies on the effects of separation anxiety during pregnancy on maternal-fetal health.