Primary postpartum haemorrhage (PPH) is an abnormal maternal bleeding within 24 hours after delivery necessitating emergency and effective clinical interventions, otherwise severe maternal health outcomes may result. Correspondingly, evidence-based PPH treatment guidelines represent the best clinical interventions for clinicians before the onset of irreversible complications. Unfortunately, low-quality treatment of PPH is widespread across the public maternity settings in Nigeria due to personal and institutional factors militating against compliance with the guidelines. Therefore, this study intends to determine the personal and institutional predictors of evidence-based treatment of PPH in the selected public maternity settings. To achieve this goal, a cross-sectional research design was adopted while close-ended questionnaires tapping into staff and maternity context were administered to a sample of nurses and midwives. 300 nurses working within a catchment area formed the target respondents and 181 nurses completed copies of the questionnaires administered. Data analysis involved both descriptive and inferential statistics underpinned by Rasch techniques of objective measurement. The results showed low compliance (Mean =495.9 logit, N=181) with the recommended treatments and nurses’ self-reported ability to implement evidence-based practice (EBP) was a statistically significant (p=0.04) predictor of compliance among the respondents. Also, most of the respondents reported a high level of desire and reinforcement by the maternity healthcare culture, but the knowledge and awareness of the best treatment was inadequate. The findings here further support the hypothesis that substandard treatment of PPH persists across the primary, secondary and tertiary levels of Nigeria’s public hospitals due to staff and institutional complexities. Finally, quality improvement interventions should prioritise supporting nurses’ clinical skills through simulation drills and exemplary clinical education programs for effective and timely PPH treatment to be administered in Nigeria’s public maternity settings.