BACKGROUND:The postpartum haemorrhage (PPH) rate in Victoria in 2009 for women having their first birth, based on information reported to the Victorian Perinatal Data Collection (VPDC), was 23.6% (primiparas). Prior to 2009 PPH was collected via a tick box item on the perinatal form. Estimated blood loss (EBL) volume is now collected and it is from this item the PPH rate is calculated. Periodic assessment of data accuracy is essential to inform clinicians and others who rely on these data of their quality and limitations. AIMS:This paper describes the results of a state-wide validation study of the accuracy of EBL volume and EBL-related data items reported to VPDC. MATERIALS AND METHODS:PPH data from a random sample of 1% of births in Victoria in 2011 were extracted from source medical records and compared with information submitted to the VPDC. Accuracy was determined, together with sensitivity, specificity, positive predictive value and negative predictive value for dichotomous items. RESULTS:Accuracy of reporting for EBL ≥ 500 mL was 97.2% and for EBL ≥ 1500 mL was 99.7%. Sensitivity for EBL ≥ 500 mL was 89.0% (CI 83.1-93.0) and for EBL ≥ 1500 mL was 71.4% (CI 35.9-91.8). Blood product transfusion, peripartum hysterectomy and procedures to control bleeding were all accurately reported in >99% of cases. CONCLUSIONS:Most PPH-related data items in the 2011 VPDC may be considered reliable. Our results suggest EBL ≥ 1500 mL is likely to be under-reported. Changes to policies and practices of recording blood loss could further increase accuracy of reporting.