Assessing Fear of Birth Scale's (FOBS) psychometric properties in the perinatal period using multicountry data is a step toward effectively screen clinically significant fear of childbirth (FOC) in maternal healthcare settings. FOBS psychometric properties were analyzed in women in the perinatal period using data from Australia, Germany, Lithuania, Poland, and Portugal. FOBS' reliability, criterion (known group and convergent), concurrent, predictive, and clinical validity were analyzed. FOBS was completed by 3431 women in pregnancy (n = 2984) or postpartum (n = 447). Sociodemographic, obstetric, neonatal, and mental health-related data, depressive and anxiety symptoms, and tokophobia severity were self-reported. FOBS has good reliability. Known-group validity was established based on differences in sociodemographic, obstetric, neonatal, and mental health-related variables. Convergent validity was found with depressive and anxiety symptoms, and birth trauma. Concurrent validity was found with tokophobia severity. FOBS scores in pregnancy predicted elective cesarean section, and postpartum depressive and anxiety symptoms. FOBS discriminates between women with and without clinically significant FOC in pregnancy and postpartum, with optimal cut-offs across countries. This multicountry study suggested that FOBS is a psychometrically strong measure that can be an effective tool to screen clinically significant FOC in the perinatal period.