Introduction <p>Exclusive Breastfeeding (EBF) confers health benefits for infants, mothers, and society. Despite this, EBF rates are low in Mauritania, and studies on factors influencing EBF are scarce. This study aims to identify factors associated with EBF practices among mothers.</p> Method <p>The study applied secondary analysis on a nationally representative sample of 1,090 mother and child pairs from the 2019–2021 Islamic Republic of Mauritania Demographic and Health Cross-sectional Survey. The factors of EBF practices among mothers were identified using a bivariate and binary logistic regression. The result is presented with a 95% confidence interval using odds ratio (OR).</p> Results <p>The prevalence of EBF among infants under 6 months was 43.3% [0.41, 0.47]. Children aged 2 months were less likely (OR = 0.41; CI [0.20, 0.82]) to be exclusively breastfed compared to those of 0 months. Working mothers were less likely (OR = 0.63; CI [0.41, 0.97]) to exclusively breastfeed their infants compared to mothers who were not working. Mothers residing in rural areas have an increased likelihood (OR = 2.21; CI [1.46, 3.34]) of EBF compared with urban areas.</p> Conclusion <p>The proportion of infants who are exclusively breastfed remains low in Mauritania. The child’s age, wealth status, maternal occupation, region, and place of residence were associated with EBF practices. To improve EBF, creating breastfeeding-friendly workplaces, extending maternity leave, and enhancing maternal health clinics and health extension programmes in various regions are suggested.</p>