Background: Because of the considerable negative effects of women's childbirth-related anxiety, fear and worries, and the time constraints that midwives perceive to assess women's antenatal emotional wellbeing, it is important that midwives can identify women with a more severe fear of birth with an easy to administer, validated tool. Objective: To investigate the ability of the two-item Fear of Childbirth Scale (FOBS) to discriminate between pregnant women with and without birth-related fear, compared with the 16-item Tilburg Pregnancy Distress Scale (TPDS). Methods: A diagnostic accuracy comparative cross-sectional study was performed, comparing two screening tests. Sensitivity, specificity, positive and negative predictive values and accuracy and discriminant property of the FOBS were determined and compared with the TPDS and with the negative affect 11-items TPDS (TPDS-NA) subscale. The TPDS and TPDS-NA were treated as reference standard to establish the discriminative potential of the FOBS for the presence or absence of antenatal birth-related fear. Participants: A sample of 396 Dutch women with uncomplicated pregnancies. Results: When compared with the 16-items TPDS, the FOBS showed a higher specificity (95%) than sensitivity (70%) to detect fear of childbirth. The FOBS items had a good predictive ability for fear and worries about the forthcoming birth (79%) and a conclusive ability for negative case-finding (92%). The FOBS showed good accuracy (89%). The FOBS discriminated women who were or were not classified as being fearful according to the TPDS (AUC. 86). When compared with the 11 items TPDS-NA subscale, the FOBS validity and accuracy decreased: sensitivity: 51%; specificity 92%; positive predictive ability 65%; negative predictive ability 88%; accuracy 83%; AUC. 82. Conclusion: When compared with the 16-items TPDS, the two-item FOBS shows to be an accurate tool for identifying the presence of antenatal birth-related fear in a sample of Dutch women with uncomplicated pregnancies.