OBJECTIVE: To assess the quality of maternal and newborn care (QMNC) in countries of the former Yugoslavia. METHOD: Women giving birth in a facility in Slovenia, Croatia, Serbia, and Bosnia-Herzegovina between March 1, 2020 and July 1, 2021 answered an online questionnaire including 40 WHO standards-based quality measures. RESULTS: A total of 4817 women were included in the analysis. Significant differences were observed across countries. Among those experiencing labor, 47.4%-62.3% of women perceived a reduction in QMNC due to the COVID-19 pandemic, 40.1%-69.7% experienced difficulties in accessing routine antenatal care, 60.3%-98.1% were not allowed a companion of choice, 17.4%-39.2% reported that health workers were not always using personal protective equipment, and 21.2%-53.8% rated the number of health workers as insufficient. Episiotomy was performed in 30.9%-62.8% of spontaneous vaginal births. Additionally, 22.6%-55.9% of women received inadequate breastfeeding support, 21.5%-62.8% reported not being treated with dignity, 11.0%-30.5% suffered abuse, and 0.7%-26.5% made informal payments. Multivariate analyses confirmed significant differences among countries, with Slovenia showing the highest QMNC index, followed by Croatia, Bosnia-Herzegovina, and Serbia. CONCLUSION: Differences in QMNC among the countries of the former Yugoslavia during the COVID-19 pandemic were significant. Activities to promote high-quality, evidence-based, respectful care for all mothers and newborns are urgently needed. CLINICALTRIALS: gov Identifier: NCT04847336.