Introduction: Approximately 3%–4% of women experience childbirth-related posttraumatic stress disorder (CB-PTSD). The City Birth Trauma Scale (City BiTS) is a questionnaire developed to assess CB-PTSD, following the criteria outlined in the Diagnostic and Statistical Manual of Mental Disorders. The aim of the present study was to evaluate the psychometric properties of the Norwegian version of this questionnaire (City BiTS-Nor). Material and Methods: A community sample of 1079 mothers completed a cross-sectional online survey. The survey included questions on sociodemographic and obstetric characteristics, the City BiTS-Nor, the Impact of Event Scale-Revised, the Edinburgh Postnatal Depression Scale, the 10-item anxiety subscale of the Hopkins Symptom Checklist, and the Bergen Insomnia Scale. Results: Confirmatory factor analysis supported a bifactor model comprising Birth-related Symptoms and General Symptoms in CB-PTSD, along with a General CB-PTSD factor that explained 58.4% of the variance. The study found high internal consistency (≥0.90), and good convergent and divergent validity were shown. Discriminant validity was evaluated by examining factors such as mode of birth, maternal complications, infant complications, parity, history of traumatic childbirth, and previous traumatic experiences. Higher General and Birth-related scores were observed in women who experienced emergency cesarean sections or instrumental vaginal births. This trend was observed in primiparous women, cases involving pregnancy and birth complications, and individuals with prior traumatic experiences. Conclusions: The City BiTS-Nor presents appropriate psychometric properties for assessing CB-PTSD symptoms according to DSM-5 criteria. The findings suggest that using the total score, along with the individual subscale scores, is justified and enhances the comprehensive assessment of CB-PTSD symptoms. These findings support the clinical utility of the City BiTS-Nor as a screening tool for CB-PTSD, with potential to differentiate childbirth-related trauma from general psychopathology and to guide targeted interventions in perinatal care.