Objective: City Birth Trauma Scale (City BiTS) is an instrument designed to evaluate and diagnose postpartum posttraumatic stress disorder (PTSD) according to the 5th edition of Diagnostic and Statistical Manual of Mental Disorders (DSM-5). No validated Swedish instrument exists to measure postpartum PTSD according to DSM-5. Therefore, the primary aim of this study was to assess the psychometric properties of the Swedish version of the City BiTS (City BiTS-Swe) and to examine the latent factor structure of postpartum PTSD. The secondary aim was to report the Swedish prevalence of PTSD following childbirth. Method: A total of 619 women, who had given birth at five clinics in the past 6-16 weeks, completed an online version of City BiTS-Swe and the Edinburgh Postnatal Depression Scale (EPDS). Additionally, sociodemographic and medical data were collected. A second questionnaire was answered by 110 women to examine reliability over time. Results: The confirmatory factor analysis using the two-factor model gave best fit to the data. We found a high internal consistency (a = .89-.87) and good test-retest reliability (ICC = 0.53-0.90). Divergent reliability with EPDS showed significant correlations with satisfying results for the subscale birth-related symptoms (r = .41). We also found discriminant validity concerning mode of birth, parity, gestational age, mental illness, history of traumatic childbirth, and history of traumatic event as expected. The prevalence of PTSD was 3.8%. Conclusions: The City BiTS-Swe is a valid and reliable instrument to assess and diagnose PTSD following childbirth.