Neonatal health is a significant global public health concern, and the first two days of life are crucial for newborn survival. Most studies on newborn postnatal care have focused on crude coverage measures, which limit the evaluation of care quality. However, evidence suggests a shift towards emphasising effective coverage, which incorporates the quality of care when measuring intervention coverage. This research aimed to assess the effective coverage of newborn postnatal care in Ethiopia while also examining its inequalities and spatial distribution. The study used secondary data from the 2016 Ethiopian Demographic and Health Survey, which was a cross-sectional community-based study. A total weighted sample of 4169 women was used for analyses. We calculated crude coverage, which is the proportion who received a postnatal check within 48 hours of birth and quality-adjusted coverage (effective coverage), which is the proportion who received a postnatal check within 48 hours of birth and reported receipt of 6 or more contents of care provided by health care providers. Concentration index and concentration curves were used to estimate the socioeconomic-related inequalities in quality-adjusted newborn postnatal care. The spatial statistic was analysed by using Arc-GIS. The crude coverage of newborn postnatal care was found to be 13.2%, while the effective coverage was 9%. High-quality postnatal care was disproportionately concentrated among the rich. A spatial variation was found in quality-adjusted coverage of newborn postnatal care across regions. The findings suggest that there is a significant gap in the coverage and quality of postnatal care for newborns across regions in Ethiopia. The low rates of coverage and effective coverage, combined with the concentration of high-quality care among the rich and the spatial variation across regions, highlight the need for targeted interventions and policies to address the inequalities in access to high-quality postnatal care for newborns.