The aims of this study were to determine prevalence of childbirth fear among uncomplicated pregnant women in Siriraj Hospital and possible associated factors. A total of 305 uncomplicated, singleton pregnant women were enrolled during early third trimester. All participants were interviewed regarding baseline demographic, social, economic, family, and obstetric characteristics. Fear of childbirth (FOC) was evaluated by Thai version of Wijma Delivery Expectancy/Experience Questionnaire Version A (W-DEQ). W-DEQ scores and level of FOC were compared between various characteristics to determine possible associated factors. Mean W-DEQ score was 51.9. Prevalence of low, moderate, high, and severe FOC were 18.4%, 64.9%, 16.1%, and 0.7%, respectively. Mean FOC score was significantly higher in women with unplanned than planned pregnancy ( = .033). Women with high to severe FOC were significantly less likely to have adequate income ( = .03), have family support ( = .02), have been told about delivery ( = .03), and have witnessed delivery ( = .01). IMPACT STATEMENT Prevalence of fear of childbirth (FOC) in Western countries varies from 8 to 27%. FOC have been related to several unwanted conditions, including obstetrics complications, operative vaginal delivery, increased analgesic use in labour, elective caesarean section, postpartum depression, and impaired maternal-infant relation. Several factors related to FOC have been reported, including maternal age, parity, gestational age, history of a vacuum or forceps extraction, previous caesarean section, previous adverse perinatal outcome, low education, low socio-economic level, psychiatric problems, personality, lack of social support, and low self-esteem. Prevalence of low, moderate, high, and severe FOC in Siriraj Hospital were 18.4%, 64.9%, 16.1%, and 0.7%, respectively. This was relatively lower than those reported from Western countries. Mean FOC score was significantly higher in women with unplanned than planned pregnancy. High to severe FOC was significantly related to low financial and family support and less understandings on delivery process. Differences in the results might be partly due to the differences in study population characteristics of Thais, including ethnics, religions, beliefs, perceptions, social structures, and social norms. Future researches are suggested to explore and understand more about social and cultural factors associated with FOC. Identification of women with high or severe degree of FOC could help in preparing the women at risk before or during pregnancy to lessen FOC in order to improve their childbirth experiences. In addition, effective interventions to reduce FOC should be developed, evaluated, and implemented in the future.