Objective: To estimate the prevalence of mistreatment in maternity care (MMC) by developing multiple-source indicators and to determine their relationship with sociodemographic and childbirth characteristics. Design: Observational and cross-sectional multicenter study. Setting: Northern Spain. Sample: 978 participants contacted by consecutive recruitment. Methods: Obstetric practices were collected from self-administered questionnaires and the available information registered in clinical records. Main Outcome Measures: 9 MMC indicators (MMCi) based on 44 variables were developed according to evidence-based practice. Results: 847 women accepted to participate (87.9% participation). The prevalence of MMCi was 4.3% (95% CI = 3.1 – 6.1) for instrumental delivery or caesarean unregistered in clinical records or performed with non-evidence-based clinical indication (UNREG/N-EB), and 48.1% (95% CI = 45.1 – 52.2) for perception of inadequate attention. Six indicators were above 40% (induction without a written consent, amniotomy performed as routine, lithotomy during pushing, suffering mother-baby separation, not having freedom to choose maternal position during labour and delivery, or to drink freely). Private facilities were associated with the use of UNREG/N-EB practices, such as instrumental delivery or caesarean, vaginal examinations, intrapartum interventions, mother-baby separation, restricted in intrapartum mobility, and inadequate analgesia. Childbirth characteristics showed differential associations with MMCi. Conclusion: This study highlights the gap between recommended standards for respectful childbirth care and actual clinical practices. Addressing MMC requires a comprehensive approach that includes both clinical data and women’s perceptions, along with the enforcement of good clinical practice policies. Future research should focus on intersectional factors and reducing disparities to ensure equitable, high-quality care for all women.