Introduction Postpartum depression (PPD) is a prevalent condition with a serious impact. The early identification of women at risk for developing PPD allows for primary prevention and the delivery of timely appropriate referrals. This study investigated the validity and reliability of the postnatal version of the Postpartum Depression Predictors Inventory-Revised (PDPI-R), an instrument widely studied internationally, in Portuguese women. Methods The sample consisted of 204 women who participated in an online cross-sectional survey. Participants completed the European Portuguese versions of the PDPI-R, the Edinburgh Postnatal Depression Scale (EPDS), and the Postnatal Negative Thoughts Questionnaire at 1-2 months postpartum. Additionally, ROC analyses were performed to conduct an exploratory analysis of the instruments' predictive validity. Results The prevalence rates of clinical postpartum depressive symptoms were 27.5 and 14.2% using the cut-off scores of 9 and 12, respectively, on the EPDS. The European Portuguese postnatal version of the PDPI-R demonstrated acceptable reliability and satisfactory construct and convergent validity. When using the EPDS > 9 cut-off score, the exploratory analyses yielded a sensitivity of 76.8% and a specificity of 73.0% with a cut-off score of 5.5 [area under the curve = 0.816]. Discussion These preliminary findings encourage the use of the postnatal version of the PDPI-R as a screening tool to identify Portuguese women at high risk for developing PPD. Subsequent assessments are needed to support the routine application of the PDPI-R both in research and for clinical purposes.