OBJECTIVES: Primary objective: to assess nine data quality metrics for 14 maternal and newborn health data elements, following implementation of an integrated, district-focused data quality intervention. SECONDARY OBJECTIVE: to consider whether assessing the data quality metrics beyond completeness and accuracy of facility reporting offered new insight into reviewing routine data quality. DESIGN: Before-and-after study design. SETTING: Primary health facilities in Gombe State, Northeastern Nigeria. PARTICIPANTS: Monitoring and evaluation officers and maternal, newborn and child health coordinators for state-level and all 11 local government areas (district-equivalent) overseeing 492 primary care facilities offering maternal and newborn care services. INTERVENTION: Between April 2017 and December 2018, we implemented an integrated data quality intervention which included: introduction of job aids and regular self-assessment of data quality, peer-review and feedback, learning workshops, work planning for improvement, and ongoing support through social media. OUTCOME MEASURES: 9 metrics for the data quality dimensions of completeness and timeliness, internal consistency of reported data, and external consistency. RESULTS: The data quality intervention was associated with improvements in seven of nine data quality metrics assessed including availability and timeliness of reporting, completeness of data elements, accuracy of facility reporting, consistency between related data elements, and frequency of outliers reported. Improvement differed by data element type, with content of care and commodity-related data improving more than contact-related data. Increases in the consistency between related data elements demonstrated improved internal consistency within and across facility documentation. CONCLUSIONS: An integrated district-focused data quality intervention-including regular self-assessment of data quality, peer-review and feedback, learning workshops, work planning for improvement, and ongoing support through social media-can increase the completeness, accuracy and internal consistency of facility-based routine data.