Background: Previously developed instruments measuring the quality of postnatal care, based on women’s experiences and views, are mainly country-specific which makes it important to have studies for specific populations. The aim of this study was to explore validity and reliability evidence of a previously developed postnatal questionnaire for women living in Sweden. Method: A cross-sectional study based on self-report questionnaire. The questionnaire included the Early Postnatal Questionnaire (EPQ), and was administered to 1061 women who gave birth in two regional hospitals in Swedish during 2017. Validity evidence of the EPQ was undertaken using principal component analysis. Regarding reliability, Cronbach’s alpha was used. Results: The questionnaire was returned by 483 postnatal women. The analysis resulted in three components: Information, Postnatal Environment and Caring Relationship. The Cronbach alpha values of the components ranged from 0.762 to 0.879. Foreign-born women scored higher (more positively) in all three components, compared to women born in Sweden. Conclusions: The results of this study suggest that the instrument EPQ is a psychometrically useful tool, suitable for both research and clinical settings. The three-component structure provides researchers with the opportunity to conduct a more detailed exploration of various aspects of postnatal care to develop postnatal care. Further studies focusing on foreign-born women’s experiences of postnatal care are warranted.